---------- >>
The LCD Thread (website)
Guide Updated: Saturday, Sep 5, 2009
Please don't e-mail or PM me. Don't be shy. Post in the thread for everybody to see, and register if you're not a member of AnandTech Forums.
NEC LCD2690WUXi review (discuss in thread)
Past thread: Archive
--------------------
Change log
--------------------
Sep 5, 2009: Added ASUS 23-26" series to Gaming: ASUS VH236H, VK246H, VK266H. Added new Samsung C-PVA panels (F2080, F2380) to Office Work, Multimedia, and sRGB Photo Editing.
Jun 9, 2009: Updated recommendations list (added 2233RZ and VX2260wm).
Jan 9, 2009: Link to http://www.flatpanelshd.com/ (new English site from flatpanels.dk)
Dec 19, 2008: Updated recommendations list and added Acer G24 to glossy LCDs list. Added English dot pitch calculator (thanks qz33).
Jul 18, 2008: Added link to a monitor adjustment guide: http://www.galacticmag.com/mon...ness-and-contrast.html
Jun 30, 2008: Fixed link to 1920x1200 scaling support table/Matrix of all Matrices.
Jun 19, 2008: Added list of glossy LCD panels.
May 11, 2008: Notes about 0-input lag VAs and link to scaling support on 1920x1200 panels.
Apr 27, 2008: Added Manufacturer - Panel Trends to Panel Types section.
Apr 8, 2008: Removed dead link to MonitorSource (monitorsrc.com).
Apr 3, 2008: Notes about Sharp ASV-type (VA) panels.
Mar 16, 2008: Added link to DigitalVersus calibration profiles. Notes about using rubbing alcohol for cleaning.
Mar 4, 2008: Notes about more "viewing angle" spec scams. 178/178 can now be a TN panel.
Feb 29, 2008: Notes about ViewSonic/EDID corruption.
Feb 15, 2008: Updated info about "image delay": it's primarily input lag, not response time. This is still a good indicator of relative performance since response time of LCDs on input lag timers (black->red transition) varies by very little.
Jan 21, 2008: Some WG CCFLs cover 97% of NTSC.
Jan 21, 2008: Added Conventions and Panel Types sections. New terms devised (dynamic range/contrast).
Jan 21, 2008: Moved Hot Deals ( tons
) and Recommendations to second post because of convenience/FF drawing bug with max post length. Recommendations will now have its own change log as well.
Dec 30, 2007: VX2435wm comes with full HDMI->DVI cable.
Dec 16, 2007: ViewSonic VX2435wm recommended for Multimedia. Replaces LP2465 for Screen Proofing (better gamma curve). FP241W removed for good (blackout problems weren't solved).
Dec 12, 2007: Acer AL2216Wbd added (value 22" LCD) (Office Work and Multimedia).
Dec 11, 2007: Prices and ranks of HTPC LCDs updated. 32" Sharp LC-32GP1U added to HTPC section. Discontinued LVM-37w3 removed.
Dec 10, 2007: Welcome the Gateway FHD2400 and Samsung 245BW to the Gaming section. FHD2400 and NEC LCD2690WUXi now in Multimedia also.
Dec 7, 2007: Updated colorimeter info: Huey->bad, Huey Pro->not so bad. More wide gamut/calibration info.
Dec 1, 2007: HP w2007 added to Multimedia recommendations.
Nov 29, 2007: Some consolidation and rearranging (mainly, in order of confidence). Changed Hardcore Gaming section to contain CRT-like LCDs only. The rest will be placed in Multimedia. Availability of 20WMGX2/215TW now limited. Philips 230WP7NS removed (no longer available). Removed FP241WZ altogether (issues/not available). "Office Work" LCDs now require matte coating, not glossy. 971P rises in ranks under Photo Editing/Print Proofing (better contrast than others).
Nov 25, 2007: 206BW, 226BW gone. Panel lotteries never stopped and response time issues continued. It is too difficult to recommend LCDs that contain panels that differ significantly. But thanks Samsung for bringing back the 215TW (recommended once again). 70GX2/90GX2 removed (discontinued).
Nov 11, 2007: HP LP2465 recommended as alternative to BenQ FP241W.
Nov 3, 2007: ViewSonic VX2255wmb recommended (overall better than 226BW models except for gaming). The VX2255wmb has no overdrive but it is fast, so you can expect a fast display with no artifacts. It has a little more input lag than the 226BWs, apparently, but it is still very suitable for gaming.
Nov 2, 2007: Added 215TW deal. It's back!
Oct 22, 2007: HP LP1965 (VA) added for Office Work. Updated 226BW/LP2065/L2045w/206BW/70GX2 panel info.
Oct 21, 2007: Pulled PX2611W only as a precaution, due to less than favorable ExtremeTech review. May re-add later if more favorable reviews show up, although the 275T seems to be a better deal for many people at this point.
Oct 20, 2007: Planar PX2611W added to Hardcore Gaming (it is as good or better than other 24" monitors listed there), and Office Work. Updated price to $950 USD, linked it to Newegg. Added lagom.nl/lcd-test to links.
Oct 14, 2007: Re-added L1952TX, AL2051W, FP241WZ, 940BF, starred them with "limited availability" since they may be available outside US.
Oct 10, 2007:
- Acer AL2051W, BenQ FP241WZ removed (discontinued). BenQ FP241W added to recommendations in place of Z version.
- Adapting to today's market, regardless of panel lotteries: Samsung 226BW added. HP LP2065 re-added. Panel lottery section cleaned up. The companies won't listen, so right now it is only hurting consumers by not recommending monitors that contain alternate panels which are still superior to others.
- LG L1952TX removed (unavailable). LG "2 ms (g2g)" models added: L1960TR (and implied recommendation of L1933TR thru Notes).
- BenQ FP93GX/Samsung 940BF removed: they simply aren't available anywhere anymore.
- 2407WFP-HC/VX1932WM RTC issues noted/company reactions.
Sep 8, 2007: Samsung 206BW added to Multimedia, L204WT removed because of slower response time. Samsung 205BW removed since it was discontinued, and replaced by HP L2045w in Office Work.
Sep 2, 2007: Image retention issues added to NEC 20WMGX2 notes.
Sep 1, 2007: Acer AL2051W deal invalid.
Aug 23, 2007: Note of 2407WFP-HC ghosting problems. Removed, for now, from the Multimedia section until a better consensus on the problems is reached.
Aug 22, 2007: Soyo 24" hot deal added.
Aug 18, 2007: Added Samsung SyncMaster 275T. Price of Philips 230WP7NS updated ($675 to $950 USD!)
Aug 8, 2007: Added info about wide gamut LCDs. Added Planar 26" and NEC 26" to Print-Target Editing. Added Planar 26" to Multimedia. Photo editing/DTP sections named more appropriately.
Jul 31, 2007: Added Westinghouse LVM-47w1 47" monitor to HTPC recommendations. Added more info about calibration and links.
Jul 26, 2007: Many new recommendations and updated prices. PigsterWiki is now MonitorSource.
Jul 17, 2007: Added section "Using Your LCD".
Jul 16, 2007: Fixed info about DVI (it can suffer from signal degradation).
Jul 14, 2007:
- The AL2051W was moved above the L226WT for Multimedia performance. At the time it was added it was very new and mostly added since it was one of the few VA panels, although at this point it has truly proven itself.
- Removed HP LP2065 from recommendations (all AMVA panels now, sorry). Updated Panel Lottery appendix also.
- Added Dell 2407WFP (non-HC A04) to Prosumer Photo Editing and Desktop Publishing recommendations. 971P still has better default color accuracy than the 2407WFP, however.
- Fixed some broken "image delay" links.
- Fixed all LCM/LCD links to match Samsung's new TFT-LCD site.
Table of Contents
i. Preface
----------------
In the confusing market of LCD monitors, The LCD Thread was created as a resource to assist users in choosing the right display for themselves. In the guide you will find a comprehensive description of the inner workings of LCD monitors, as well as recommendations for each usage category. Participation in the thread and discussion is encouraged, as is posting daily LCD headlines. Feel free to ask for LCD recommendations in the thread if you are unsure or have specific criteria. Questions about LCDs or general display technologies are also welcome. My goal is to personally respond to each one of you, and thus far I have met that goal. Thank you for taking the time to visit. I hope you enjoy your time here and I hope to keep this resource updated as much as possible.
A previous thread containing more than 4000 posts is available here: Archive
Discussion has been moved to this new thread because of load times.
Since the search facilities at AnandTech are still under construction, the best way to search these threads is to set the "messages per page" parameter in your forum profile to 500 and use your browser's Find function instead for each page.
----------------------
ii. Conventions
----------------------
This document assumes you have some basic understanding of optics and display technology, in particular the concepts below.
iii. Primer
----------------
When you're looking to buy an LCD, you must take into account their many parameters. Some LCDs are better than others for certain purposes. For instance, ones with a fast response time and low input lag are ideal for games. LCDs with high contrast are great for gaming too, but are even more suitable for movies. You will have to find one (or even two) that can accommodate all of your needs.
Color depth, or bit depth, is one major factor in choosing an LCD. LCDs that offer true 8-bit color depth will provide a more contiguous grayscale with no dithering artifacts. They are better especially in the darker shades of color. 6-bit LCDs tend to experience artifacts in darker colors, although more recent ones that implement an algorithm called Hi-FRC (high frame rate control) have made the artifacts virtually invisible to the human eyes. TN panels are physically incapable of producing 256 levels of gray (true 8-bit), so naturally, they must employ Hi-FRC. TN panels also happen to be low in contrast, so this gives 6-bit panels altogether a bad connotation. On the other hand, "true 8-bit" LCDs are almost always equipped with higher contrast panels and wide viewing angles. Keep in mind that color depth is a factor independent of panel technology, at least for VA and IPS. A VA panel is not always 8-bit!
All desktop LCDs are based on a-Si (amorphous silicon) TFT (thin film transistor) technology. We effectively have three major classes of TFTs: TN, VA (MVA/PVA), and S-IPS. Each of these main classes has its own subclasses, but the differences tend to be minor. We will first discuss the most primitive TFT technology, twisted nematic (TN).
TN displays are known for their excellent response time, but also poor viewing angle. The vertical viewing angle can be especially limited, making the use of portrait mode (pivot) difficult. Most people sit right in front of their screen without moving, so the problem may be insignificant. TNs tend to produce a less uniform brightness output than other panels, so looking at large areas of a light color can be uncomfortable at any angle. When you look at a TN from below, the image will appear almost fully inverted.
Despite their viewing angle problems, TN panels make great gaming displays. Modern TNs with no speed acceleration technology reach an 18-25 ms response time, the time it takes for one crystal to transition from one color to another color (all transitions take a slightly different amount of time, especially when different color pairs are involved). LCDs with slow response time exhibit effects of ghosting, a double image lagging behind the main image, in moderate to very fast motion, and stuttering in instances of slow motion. TNs often also have the least input lag, a delay in which the LCD's image is a couple frames behind what's being sent. This is, potentially, a make-it-or-break-it factor that depends on how sensitive you are and whether you can adapt to it, and it will be covered more in-depth in the next section. Please note that all measurements mentioned here of image delay are input lag plus the response time it takes to show a digital timer's number segments on the LCD (described more in-depth under Input Lag section).
Next up are the VA (vertical alignment) panels: MVA (multidomain vertical alignment) and PVA (patterned vertical alignment). In actuality, both have very similar characteristics even though they operate by different means. Typical VAs offer around twice the maximum brightness of the average TN panel. They are also famous for their high dynamic range and low black level. Response time, with RTC (response time compensation, a crystal acceleration technology) is right up there with TN panels that aren't paired with the same tech. Their input lag, partly caused by RTC, tends to be the worst of the three most popular panels. The total image delay (again, mainly input lag) can get up to 70 ms in the worst cases with most large VA-based screens averaging around 30-50 ms. It's usually not as much as an issue for smaller VA panels, although one, the Acer AL2051W, reaches 34 ms on average.
MVA and PVA panels are generally economical (MVA the cheaper of the two), but are still less present on the market than TNs. Their viewing angle is dramatically better, although slightly yellowish tinting is noticeable at certain angles. VA panels with RTC are generally a good choice for just about anything, if you can find one at the size and price you desire. Unfortunately, their input lag could eliminate the choice altogether for you (especially when it comes to big screens).
Sharp has a line of panels named ASV (Advanced Super View), named for its wide viewing angle. This is also a VA technology but currently, at least in the US market, it is only used in TVs. It has been reputed to deliver excellent image quality and response time.
Lastly, S-IPS panels are the choice of the professionals. They boast near-perfect viewing angles, and often offer better color reproduction than VA panels. Response time, with RTC, is right in the ballpark of the VA panels with RTC. This panel type is probably the sweet spot for having good colors and low response, as well as having a medium input lag time. Their image delay tends to be slightly worse than TNs (that average 15 ms or so). In a few cases they can go up to 30 ms but most IPS panels hang in there well enough, not reaching the magnitude of a VA panel.
IPS panels suffer more from SDE (screen door effect), a phenomenon in which your eyes are able to visualize all the individual pixels on the screen. In this way, they can cause more eye strain. This isn't an issue for the majority of users, and may only happen when working with text or other light-background material. Their brightness is typically somewhere between that of TNs and VAs, but variants such as AS-IPS can offer white levels of up to 470 nits and lifelike, vibrant colors. In most cases however, this maximum brightness does not indicate a usable value. Their grayscale reproduction must be sacrificed at somewhere over 300 nits. Unfortunately their availability is extremely limited, and prices are soaring. It is expected that they will soon disappear into a pro-only market carrying a hefty premium with their price tags.
If you'd like more condensed information on the panel types discussed above, check out the Matrix of all Matrices.
We have just gotten through discussing the trends of all the major panel types. Beyond this point, the differences are model-specific.
LCD manufacturers offer two types of glass: anti-glare (sometimes called hard 3H or 4H coating) and glossy. Anti-glare LCDs account for more than 90% of the desktop market. These coatings reduce the glare that you may be used to from old CRTs, but they do it as the cost of dynamic range, clarity, and color vibrance. Glossy coatings increase dynamic range by a good amount but can be frustrating to use if bright lights happen to be shining right at the screen. They exhibit an excessive amount of glare in these conditions, so they should be used in rather dim but consistently lit environments for the best results. Glossy panels tend to crush darker details and exaggerate midtones.
----------------------
I. Panel Types
----------------------
-----------------------------------------------
II. Technology and Limitations
-----------------------------------------------
III. Multimedia LCDs/Input Options
-----------------------------------------------
IV. Specifications
-----------------------------------------------
-----------------------------------------------
V. Recommendations
-----------------------------------------------
VI. Using Your LCD
-----------------------------------------------
Appendix A. A Few Words About "Panel Lotteries"
--------------------------------------------------------------------
Several manufacturers, including Dell and Samsung, have played the panel "bait and switch" game thinking no one would notice. A controversial practice called a "panel lottery" by others, they will originally release a good panel (for reviewers) and switch to an inferior one later on. Dell first put an S-IPS in their 2007WFP and later switched to an S-PVA, whose performance was deemed very low compared to the S-IPS. Samsung originally was making "S" (Samsung) TN panels for their 226BW, until they outsourced their production to AU Optronics ("A"), CMO ("C"), and CPT ("P"). The A, C, and P panels performed poorly at the default color settings. All of their colors were equal after calibration, although the C panel had more issues with response time. Since many folks don't own a colorimeter, they will end up with a panel that can't display colors with the same fidelity as the original "S" panel. Later, both Dell and Samsung began hiding the panel information from the service menu and the back panel.
In an interview, Samsung stated that after April 1st they would release only "S" panels (in France). Three Frenchmen discovered 2 A panels and 1 C panel with their 226BWs manufactured after April 1.
Dell and Samsung claim that they did this because of stock problems. Well, if they didn't have enough stock why did they continue selling it under the same model name? It obviously makes it frustrating for users who try to pick the right panel. It doesn't help that the "alternate panel" often falls way behind the original.
HP also has switched to AMVA in its HP LP2065 model in some cases, but at least they registered the change with the FCC in publicly available format unlike Dell/Samsung who really kept it under the covers. HP did keep a label on their box also indicating the panel.
The main purpose of this section was to raise awareness of this problem, and hopefully send a message to the vendors involved that the panel switching needs to stop.
Update (10/10/2007): Unfortunately, nothing has changed since so I am back to recommending the monitors, simply because their alternate panels are still better than other LCDs.
Update (11/25/2007): Better LCDs have appeared since, so the 206BW and 226BW are gone. They both have response time problems, blue color hues, etc... Hopefully Samsung will change their mind for the better with the 2032BW and 2232BW. Samsung, use whatever panels you please, just make sure they all have roughly consistent performance.
------------------------------------------------
Appendix B. Additional Resources
------------------------------------------------
No review or resource can be 100% accurate, but these sites may help you in your buying decision.
- IMPORTANT NOTE: For reasons of convenience, the recommendations have been moved to the second post (under this one).
The LCD Thread (website)
Guide Updated: Saturday, Sep 5, 2009
Please don't e-mail or PM me. Don't be shy. Post in the thread for everybody to see, and register if you're not a member of AnandTech Forums.
NEC LCD2690WUXi review (discuss in thread)
Past thread: Archive
--------------------
Change log
--------------------
Sep 5, 2009: Added ASUS 23-26" series to Gaming: ASUS VH236H, VK246H, VK266H. Added new Samsung C-PVA panels (F2080, F2380) to Office Work, Multimedia, and sRGB Photo Editing.
Jun 9, 2009: Updated recommendations list (added 2233RZ and VX2260wm).
Jan 9, 2009: Link to http://www.flatpanelshd.com/ (new English site from flatpanels.dk)
Dec 19, 2008: Updated recommendations list and added Acer G24 to glossy LCDs list. Added English dot pitch calculator (thanks qz33).
Jul 18, 2008: Added link to a monitor adjustment guide: http://www.galacticmag.com/mon...ness-and-contrast.html
Jun 30, 2008: Fixed link to 1920x1200 scaling support table/Matrix of all Matrices.
Jun 19, 2008: Added list of glossy LCD panels.
May 11, 2008: Notes about 0-input lag VAs and link to scaling support on 1920x1200 panels.
Apr 27, 2008: Added Manufacturer - Panel Trends to Panel Types section.
Apr 8, 2008: Removed dead link to MonitorSource (monitorsrc.com).
Apr 3, 2008: Notes about Sharp ASV-type (VA) panels.
Mar 16, 2008: Added link to DigitalVersus calibration profiles. Notes about using rubbing alcohol for cleaning.
Mar 4, 2008: Notes about more "viewing angle" spec scams. 178/178 can now be a TN panel.
Feb 29, 2008: Notes about ViewSonic/EDID corruption.
Feb 15, 2008: Updated info about "image delay": it's primarily input lag, not response time. This is still a good indicator of relative performance since response time of LCDs on input lag timers (black->red transition) varies by very little.
Jan 21, 2008: Some WG CCFLs cover 97% of NTSC.
Jan 21, 2008: Added Conventions and Panel Types sections. New terms devised (dynamic range/contrast).
Jan 21, 2008: Moved Hot Deals ( tons
) and Recommendations to second post because of convenience/FF drawing bug with max post length. Recommendations will now have its own change log as well.Dec 30, 2007: VX2435wm comes with full HDMI->DVI cable.
Dec 16, 2007: ViewSonic VX2435wm recommended for Multimedia. Replaces LP2465 for Screen Proofing (better gamma curve). FP241W removed for good (blackout problems weren't solved).
Dec 12, 2007: Acer AL2216Wbd added (value 22" LCD) (Office Work and Multimedia).
Dec 11, 2007: Prices and ranks of HTPC LCDs updated. 32" Sharp LC-32GP1U added to HTPC section. Discontinued LVM-37w3 removed.
Dec 10, 2007: Welcome the Gateway FHD2400 and Samsung 245BW to the Gaming section. FHD2400 and NEC LCD2690WUXi now in Multimedia also.
Dec 7, 2007: Updated colorimeter info: Huey->bad, Huey Pro->not so bad. More wide gamut/calibration info.
Dec 1, 2007: HP w2007 added to Multimedia recommendations.
Nov 29, 2007: Some consolidation and rearranging (mainly, in order of confidence). Changed Hardcore Gaming section to contain CRT-like LCDs only. The rest will be placed in Multimedia. Availability of 20WMGX2/215TW now limited. Philips 230WP7NS removed (no longer available). Removed FP241WZ altogether (issues/not available). "Office Work" LCDs now require matte coating, not glossy. 971P rises in ranks under Photo Editing/Print Proofing (better contrast than others).
Nov 25, 2007: 206BW, 226BW gone. Panel lotteries never stopped and response time issues continued. It is too difficult to recommend LCDs that contain panels that differ significantly. But thanks Samsung for bringing back the 215TW (recommended once again). 70GX2/90GX2 removed (discontinued).
Nov 11, 2007: HP LP2465 recommended as alternative to BenQ FP241W.
Nov 3, 2007: ViewSonic VX2255wmb recommended (overall better than 226BW models except for gaming). The VX2255wmb has no overdrive but it is fast, so you can expect a fast display with no artifacts. It has a little more input lag than the 226BWs, apparently, but it is still very suitable for gaming.
Nov 2, 2007: Added 215TW deal. It's back!
Oct 22, 2007: HP LP1965 (VA) added for Office Work. Updated 226BW/LP2065/L2045w/206BW/70GX2 panel info.
Oct 21, 2007: Pulled PX2611W only as a precaution, due to less than favorable ExtremeTech review. May re-add later if more favorable reviews show up, although the 275T seems to be a better deal for many people at this point.
Oct 20, 2007: Planar PX2611W added to Hardcore Gaming (it is as good or better than other 24" monitors listed there), and Office Work. Updated price to $950 USD, linked it to Newegg. Added lagom.nl/lcd-test to links.
Oct 14, 2007: Re-added L1952TX, AL2051W, FP241WZ, 940BF, starred them with "limited availability" since they may be available outside US.
Oct 10, 2007:
- Acer AL2051W, BenQ FP241WZ removed (discontinued). BenQ FP241W added to recommendations in place of Z version.
- Adapting to today's market, regardless of panel lotteries: Samsung 226BW added. HP LP2065 re-added. Panel lottery section cleaned up. The companies won't listen, so right now it is only hurting consumers by not recommending monitors that contain alternate panels which are still superior to others.
- LG L1952TX removed (unavailable). LG "2 ms (g2g)" models added: L1960TR (and implied recommendation of L1933TR thru Notes).
- BenQ FP93GX/Samsung 940BF removed: they simply aren't available anywhere anymore.
- 2407WFP-HC/VX1932WM RTC issues noted/company reactions.
Sep 8, 2007: Samsung 206BW added to Multimedia, L204WT removed because of slower response time. Samsung 205BW removed since it was discontinued, and replaced by HP L2045w in Office Work.
Sep 2, 2007: Image retention issues added to NEC 20WMGX2 notes.
Sep 1, 2007: Acer AL2051W deal invalid.
Aug 23, 2007: Note of 2407WFP-HC ghosting problems. Removed, for now, from the Multimedia section until a better consensus on the problems is reached.
Aug 22, 2007: Soyo 24" hot deal added.
Aug 18, 2007: Added Samsung SyncMaster 275T. Price of Philips 230WP7NS updated ($675 to $950 USD!)
Aug 8, 2007: Added info about wide gamut LCDs. Added Planar 26" and NEC 26" to Print-Target Editing. Added Planar 26" to Multimedia. Photo editing/DTP sections named more appropriately.
Jul 31, 2007: Added Westinghouse LVM-47w1 47" monitor to HTPC recommendations. Added more info about calibration and links.
Jul 26, 2007: Many new recommendations and updated prices. PigsterWiki is now MonitorSource.
Jul 17, 2007: Added section "Using Your LCD".
Jul 16, 2007: Fixed info about DVI (it can suffer from signal degradation).
Jul 14, 2007:
- The AL2051W was moved above the L226WT for Multimedia performance. At the time it was added it was very new and mostly added since it was one of the few VA panels, although at this point it has truly proven itself.
- Removed HP LP2065 from recommendations (all AMVA panels now, sorry). Updated Panel Lottery appendix also.
- Added Dell 2407WFP (non-HC A04) to Prosumer Photo Editing and Desktop Publishing recommendations. 971P still has better default color accuracy than the 2407WFP, however.
- Fixed some broken "image delay" links.
- Fixed all LCM/LCD links to match Samsung's new TFT-LCD site.
Table of Contents
- i. Preface
ii. Conventions
iii. Primer
I. Panel Types
II. Technology and Limitations
III. Multimedia LCDs/Input Options
IV. Specifications
V. Recommendations (Post II)
VI. Using Your LCD
Appendix A. A Few Words About "Panel Lotteries"
Appendix B. Additional Resources
Appendix C. LCD Module Manufacturers
Appendix D. Issues with Specific Models
Appendix E. Glossy LCDs Listing
i. Preface
----------------
In the confusing market of LCD monitors, The LCD Thread was created as a resource to assist users in choosing the right display for themselves. In the guide you will find a comprehensive description of the inner workings of LCD monitors, as well as recommendations for each usage category. Participation in the thread and discussion is encouraged, as is posting daily LCD headlines. Feel free to ask for LCD recommendations in the thread if you are unsure or have specific criteria. Questions about LCDs or general display technologies are also welcome. My goal is to personally respond to each one of you, and thus far I have met that goal. Thank you for taking the time to visit. I hope you enjoy your time here and I hope to keep this resource updated as much as possible.
A previous thread containing more than 4000 posts is available here: Archive
Discussion has been moved to this new thread because of load times.
Since the search facilities at AnandTech are still under construction, the best way to search these threads is to set the "messages per page" parameter in your forum profile to 500 and use your browser's Find function instead for each page.
----------------------
ii. Conventions
----------------------
This document assumes you have some basic understanding of optics and display technology, in particular the concepts below.
- Bit Depth: The number of colors an LCD can reproduce (color resolution). During display calibration in software, bit depth is reduced in favor of accuracy.
- Resolution: Width by height of the active viewing portion of the panel, measured in pixels.
- Brightness: The amount of light emitted by the display device.
- Black Level: The amount of light emitted by the display device when displaying black (no display device can show black perfectly, but LCDs are worse here).
- Dot Pitch: The size of one pixel on the screen.
- Primary: Red, green, or blue, each of which is combined to show various colors other than black.
- Saturation: A color's intensity (essentially, how far away it is from being neutral/gray). e.g., kites usually contain many saturated colors, unlike rocks.
- Tint: A tendency of one particular color to be more saturated.
- White: The presence of all primaries, representing the LCD's ability to show a balanced image without a tint in, or tendency toward any particular primary (red, green, or blue).
- Black: The absence of color, representing how well the LCD can block 100% of incoming backlight (transmissive/desktop LCD type).
- Grayscale: A scale containing shades of gray that the LCD can display. Max of 256 shades for a 8-bit color resolution per primary.
- Burn/Color Burn: An overabundance of a particular color in an area. For example, a grayscale gradient may be burnt with white at the end, preventing the LCD from showing lighter tones as anything except white itself.
- Image Persistence/Burn In: The residual leftover of a previously-shown image on an LCD due to that image being displayed for too long. This is similar to phosphor burn-in on CRTs. The more you use your LCD, the quicker you may have this issue when displaying images for prolonged periods of time. The best cure is to turn off the LCD for the amount of time the burnt-in image was displayed.
- Contrast: (Not the same as "contrast ratio.") The ability of an LCD to distinguish between several colors tones across the grayscale and provide details. Reduced with poor viewing angle stability, low bit depth, and bad calibration.
- Dynamic Range: The ratio of the brightest tone an LCD can display to the darkest one (often specified as "contrast ratio").
Other sites refer to dynamic range as contrast, but I feel that this is incorrect since contrast and dynamic ratio, as defined here, are two different ideas. Note they are probably used interchangeably in this thread as well. Only distinguish between the two if they are both used in the same paragraph. Otherwise, you may assume those talking about contrast are actually talking about dynamic range. I recommend using terms like "low black level", "good brightness", and "good detail" to be more clear about the display's properties.
iii. Primer
----------------
When you're looking to buy an LCD, you must take into account their many parameters. Some LCDs are better than others for certain purposes. For instance, ones with a fast response time and low input lag are ideal for games. LCDs with high contrast are great for gaming too, but are even more suitable for movies. You will have to find one (or even two) that can accommodate all of your needs.
Color depth, or bit depth, is one major factor in choosing an LCD. LCDs that offer true 8-bit color depth will provide a more contiguous grayscale with no dithering artifacts. They are better especially in the darker shades of color. 6-bit LCDs tend to experience artifacts in darker colors, although more recent ones that implement an algorithm called Hi-FRC (high frame rate control) have made the artifacts virtually invisible to the human eyes. TN panels are physically incapable of producing 256 levels of gray (true 8-bit), so naturally, they must employ Hi-FRC. TN panels also happen to be low in contrast, so this gives 6-bit panels altogether a bad connotation. On the other hand, "true 8-bit" LCDs are almost always equipped with higher contrast panels and wide viewing angles. Keep in mind that color depth is a factor independent of panel technology, at least for VA and IPS. A VA panel is not always 8-bit!
All desktop LCDs are based on a-Si (amorphous silicon) TFT (thin film transistor) technology. We effectively have three major classes of TFTs: TN, VA (MVA/PVA), and S-IPS. Each of these main classes has its own subclasses, but the differences tend to be minor. We will first discuss the most primitive TFT technology, twisted nematic (TN).
TN displays are known for their excellent response time, but also poor viewing angle. The vertical viewing angle can be especially limited, making the use of portrait mode (pivot) difficult. Most people sit right in front of their screen without moving, so the problem may be insignificant. TNs tend to produce a less uniform brightness output than other panels, so looking at large areas of a light color can be uncomfortable at any angle. When you look at a TN from below, the image will appear almost fully inverted.
Despite their viewing angle problems, TN panels make great gaming displays. Modern TNs with no speed acceleration technology reach an 18-25 ms response time, the time it takes for one crystal to transition from one color to another color (all transitions take a slightly different amount of time, especially when different color pairs are involved). LCDs with slow response time exhibit effects of ghosting, a double image lagging behind the main image, in moderate to very fast motion, and stuttering in instances of slow motion. TNs often also have the least input lag, a delay in which the LCD's image is a couple frames behind what's being sent. This is, potentially, a make-it-or-break-it factor that depends on how sensitive you are and whether you can adapt to it, and it will be covered more in-depth in the next section. Please note that all measurements mentioned here of image delay are input lag plus the response time it takes to show a digital timer's number segments on the LCD (described more in-depth under Input Lag section).
Next up are the VA (vertical alignment) panels: MVA (multidomain vertical alignment) and PVA (patterned vertical alignment). In actuality, both have very similar characteristics even though they operate by different means. Typical VAs offer around twice the maximum brightness of the average TN panel. They are also famous for their high dynamic range and low black level. Response time, with RTC (response time compensation, a crystal acceleration technology) is right up there with TN panels that aren't paired with the same tech. Their input lag, partly caused by RTC, tends to be the worst of the three most popular panels. The total image delay (again, mainly input lag) can get up to 70 ms in the worst cases with most large VA-based screens averaging around 30-50 ms. It's usually not as much as an issue for smaller VA panels, although one, the Acer AL2051W, reaches 34 ms on average.
MVA and PVA panels are generally economical (MVA the cheaper of the two), but are still less present on the market than TNs. Their viewing angle is dramatically better, although slightly yellowish tinting is noticeable at certain angles. VA panels with RTC are generally a good choice for just about anything, if you can find one at the size and price you desire. Unfortunately, their input lag could eliminate the choice altogether for you (especially when it comes to big screens).
Sharp has a line of panels named ASV (Advanced Super View), named for its wide viewing angle. This is also a VA technology but currently, at least in the US market, it is only used in TVs. It has been reputed to deliver excellent image quality and response time.
Lastly, S-IPS panels are the choice of the professionals. They boast near-perfect viewing angles, and often offer better color reproduction than VA panels. Response time, with RTC, is right in the ballpark of the VA panels with RTC. This panel type is probably the sweet spot for having good colors and low response, as well as having a medium input lag time. Their image delay tends to be slightly worse than TNs (that average 15 ms or so). In a few cases they can go up to 30 ms but most IPS panels hang in there well enough, not reaching the magnitude of a VA panel.
IPS panels suffer more from SDE (screen door effect), a phenomenon in which your eyes are able to visualize all the individual pixels on the screen. In this way, they can cause more eye strain. This isn't an issue for the majority of users, and may only happen when working with text or other light-background material. Their brightness is typically somewhere between that of TNs and VAs, but variants such as AS-IPS can offer white levels of up to 470 nits and lifelike, vibrant colors. In most cases however, this maximum brightness does not indicate a usable value. Their grayscale reproduction must be sacrificed at somewhere over 300 nits. Unfortunately their availability is extremely limited, and prices are soaring. It is expected that they will soon disappear into a pro-only market carrying a hefty premium with their price tags.
If you'd like more condensed information on the panel types discussed above, check out the Matrix of all Matrices.
We have just gotten through discussing the trends of all the major panel types. Beyond this point, the differences are model-specific.
LCD manufacturers offer two types of glass: anti-glare (sometimes called hard 3H or 4H coating) and glossy. Anti-glare LCDs account for more than 90% of the desktop market. These coatings reduce the glare that you may be used to from old CRTs, but they do it as the cost of dynamic range, clarity, and color vibrance. Glossy coatings increase dynamic range by a good amount but can be frustrating to use if bright lights happen to be shining right at the screen. They exhibit an excessive amount of glare in these conditions, so they should be used in rather dim but consistently lit environments for the best results. Glossy panels tend to crush darker details and exaggerate midtones.
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I. Panel Types
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- TN
- Good response time
- Very good dynamic range (400:1 with older generation, 700 - 1000:1 with newer gen TNs)
- Poor vertical viewing angle (especially from below)
- Poor screen uniformity and stability (white can look "dirty"), which can reduce perceived contrast
- Lateral viewing angle is not great (darker/lighter details can appear and disappear depending on the angle)
- 8-bit gradient (16.7M colors) through dithering and FRC
- Lack of true 8-bit DAC causes color tinting, fringing, and burning in gradients and poor reproduction of darker tones
- Very unlikely to get image persistence
- Low input lag (lower latency in screen update)
- Economical, but more prone to backlight bleeding and QC (quality control) problems than other panel types, too
Target Audience:
Gamers, general use (Word/Excel) who don't mind a poorer viewing angle. Less suitable for movies and poor for photo editing.
- VA
- Decent response time (varies)
- Great dynamic range (1000:1 - 1500:1)
- Horizontal color shift (certain gray tones rapidly shift at just a few degrees, worse than TNs in many cases)
- Image details absent at perpendicular angle
- Good vertical viewing angle
- Good screen uniformity (white is uniform and does not shift at angles, contrast is decent)
- 8-bit gradient (16.7M colors) through true 8-bit DAC (although dithering is possible with certain models)
- True 8-bit DAC allows better reproduction of gradients and sometimes better dark tones than TN panels
- Unlikely to get image persistence
- High input lag (high latency in screen update)
- Good value, and the least QC problems of all panels
Target Audience:
Gamers, general use (Word/Excel) who want a more stable viewing angle. OK for photo editing, although beware of color shifting. Not bad for movies, but not always great due to color shift.
- IPS
- Decent response time
- Medium dynamic range (400:1) or higher for AS-IPS/H-IPS/A-TW-IPS (700:1)
- Minimal color shift at any viewing angle (only slight brightness reduction, and very little gamma/tint shift)
- Image details present across entire screen
- Good screen uniformity (white is uniform and does not shift at angles, contrast is amazing)
- 8-bit gradient (16.7M colors) through true 8-bit DAC (although dithering is possible with certain models)
- True 8-bit DAC allows better reproduction of gradients and sometimes better dark tones than TN panels
- More neutral grayscale reproduction and warmer, less harsh image (most like a CRT) than S-PVA panels
- Medium input lag (low or high depending on model)
- More susceptible to image persistence
- Tends to be very expensive although benefits can be visible to normal users
- Prone to quality control problems: read reviews
Target Audience:
Photo editors will crave this type of panel. IPS-type panels are suitable and generally better for anything else too, including gaming and general use. Some people may prefer an S-PVA for higher dynamic range but an IPS panel, due to its viewing angle characteristics, probably has a higher contrast (ability of the LCD to reliably reproduce tones and nuances).
- Manufacturer - Panel Trends
- Acer - almost always AUO, I believe this company is related to BenQ
- Apple - mostly LG Philips LCD IPS panels
- BenQ - tends to use AUO almost exclusively, and has resorted to CMO in some cases
- ChiMei - CMO brand
- Dell - many LG Philips and Samsung panels (especially bigger ones), but can use AUO and CMO as well
- Gateway - don't really know, but they have definitely used some Samsungs
- Hanns.G - all Hannstar panels
- HP - LG Philips, AUO, Samsung, CMO, almost anything
- LG - many LG Philips and CMO panels, also uses some CPT panels
- NEC - almost exclusively Samsung and LG Philips panels. Some medical displays made by NEC themselves.
- Planar/DoubleSight - mostly Samsung, LG Philips
- Samsung - almost always Samsung panels, but some models (226BW) have had panels from CMO, CPT, and AUO also!
- ViewSonic - lots of CMOs, occasionally a Samsung or AUO
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II. Technology and Limitations
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- Native Resolution and Scaling
LCDs are made with a fixed set of pixels whose width times height is called the "native resolution". That means that any material going into the LCD must be scaled to fit that pixel matrix unless it's already in the correct resolution. Generally, three options are given by either the graphics card or the monitor when it comes to scaling: 1:1 (also called "centered mode" or "pixel mapping"), aspect ratio scaling (also called "4:3"), and normal scaling (also "Fill"). All of these options except for centered mode distort the image. With centered mode, you simply have black filling the remainder of the screen with the actual lower resolution image in the center of the monitor. Aspect ratio gives you just one set of black bars on whichever side is the most convenient. Although "aspect ratio" mode still has to perform some scaling, it does less than the "normal scaling" which interpolates the entire image to fill the bigger screen, regardless of its aspect ratio. Therefore, the latter option can cause the image to be stretched.
The quality of scalers in both the graphics card and the monitor vary. Most NVIDIA cards should let you control the scaling with the control panel, although some have had mixed results with ATI cards (and they generally only give you the "1:1" and "Fill" modes. Intel adapters allow you to choose all three modes. Most monitors above 22" have their own set of scaling options, with few 22" or under having the same options.
- Black Level and Uniformity
LCDs can not display a true black due to some technical reasons. Black level is a measurement of how much light is let through when black is requested, and it is usually measured in candelas per square meter, the same unit as a "nit". When the black level is above zero nits for an LCD, light is said to be leaking or bleeding. LCDs, not unlike other technologies, can suffer from screen uniformity problems. Light may leak more in some areas of the screen than others. Often, it leaks more around a couple of edges (the notorious "backlight bleeding"). When light bleeds, black will look a dark gray or bluish-gray, depending on the backlight's color temperature.
Black level and light leakage can depend on several factors, including LC (liquid crystal) mode/arrangement (e.g. PVA, TN), cell gap, polarizer quality, and thermal fluctuation within the panel. Backlight bleeding can also be caused by pressure on the panel that goes away after a week or so, like in the case of the NEC 20WMGX2. In the right situations (a bit of ambient light), a glossy coating can improve the perceived black level. Most LCDs reach a black level of 0.20 - 0.60 nits, while maintaining a white level from 120 - 220 nits. Uniformity highly varies, although Grade A S-IPS panels made by LG Philips tend to have great homogeneity and a small amount of light leakage. Conversely, the 22" TNs from Chi Mei are known to have a lot of bleeding at the top and bottom of the screen, but, for many, this can be justified by the latter's very low price.
- Brightness Control
Brightness on an LCD is controlled primarily by the matrix itself. The maximum brightness of white is determined by the light output at the backlight's full power and the matrix's non-blocking state.
A secondary method of brightness control involves PWM (pulse width modulation) of the LCD backlight. This is done at a very fast rate (over 200 Hz) so it is generally not considered irritating to the eyes like a 60 Hz CRT.
- Backlight and Color Gamut
Desktop LCDs use a mode called transmissive that utilizes only a backlight, as opposed to transflective and reflective LCDs that partially or fully get their light from a source in front of the screen like the sun. The backlight emits white as well as it can, and the color filter splits this into red, green, and blue components. The whiter the white, the redder the red, the greener the green, and so on. Since red, green, and blue can produce almost any color, the range of colors an LCD can display is directly dependent on how pure the color components are. Typical backlights produce a white that yields 72% coverage of the NTSC color space standard. Newer backlights use different phosphors that can effectively cover 92-97% of the NTSC space. LED backlights, which are not yet very common in LCDs, can cover up to 114% of the same color space.
Having a higher gamut with the same bit depth has its disadvantages. A gamut specifies the boundary of the color spectrum that the LCD can display, but it does not specify the number of colors that it can display. The number of colors an LCD can display is determined by its bit depth (usually 6 bit or 8 bit). An 8 bit-per-subpixel (or 24 bit-per-pixel) LCD can show as many as 16.7M ((2^8)^3) colors, while a 6 bit (or 18 bit) LCD can only truly show 262K ((2^6)^3) colors. With a purer white to shutter (wider gamut) but the same shuttering precision (bit depth), the LCs can output a range of colors in the same precision only at the maximum gamut. Therefore, they will not to be able to display the same intermediate color tones as LCs separating a 72%-gamut backlight's white, without using dithering or FRC (frame rate control), methods of color emulation. Right now, only pricey professional LCDs implement this gamut emulation. This limitation doesn't generally drive people away from the higher gamut LCDs. The higher gamut LCDs provide a more natural and believable picture (a real weakness of lower-gamut LCDs) since they cover more of the visible spectrum.
- Response Time
Moving pictures present a problem for LCD technology, more than competing phosphor-based technologies like CRT and plasma (impulse-type). LCDs are called "hold-type" displays, because they hold their image until told otherwise. They must gradually twist to another position in order to display a new color. During this twisting period, trails and ghosting are left behind as one pixel tries to fall and another tries to rise. Since nematic liquid crystals can fall much faster than they can rise, the ghost tends to be either considerably lighter or darker than the original image.
LCD module manufacturers managed to reduce the viscosity and cell gap of the liquid crystal, which reduced response time. This had the disadvantage of limiting the color depth to just 6-bit (262K colors).
Another proposed way of reducing the ghost image (effectively emphasizing the "real" image) was to use overdrive, a means of response time compensation that sends bursts of voltage to increase a crystal's transition speed in both rise and decay. This has been especially helpful for reducing the response time of MVA and IPS panels, making them a lot more suitable for moving pictures. With well-controlled overdrive, the typical rise and fall response time of a PVA panel is around 20 ms. Gray-to-gray response time for a similar MVA-based LCD reaches 8.5 ms on average.
This comparison shows the moving image characteristics of the NEC 20WMGX2, an overdriven IPS-based panel, against a Sony SDM-HS95D, a TN panel that does not incorporate overdrive technology.
A downside of overdrive is the "overshoot" that it can cause when the burst of voltage is too high. This means very bright and dark artifacts can occur around the moving object. These are generally accepted as being worse than the ghosting itself. Algorithms are improving though, and the best LCDs have an average overdrive error percentage of lower than 5. There can be a few situations where the ghosting will be worse, as seen with the 60% maximum RTC error on the NEC 20WMGX2, but most users will accept a lower response time for 95% of transitions and a higher one for the remaining five percent.
According to BenQ, the main roadblock nowadays is retinal persistence. They proposed a method of black data insertion that wipes the eyes of the previous image by using a scanning black bar. The most common implementation is the scanning backlight mechanism. In this method, there are several backlights lined up horizontally that are switched off in each frame. The effect closely resembles lines of decaying phosphors on a CRT screen. It has shown some success in making LCD gaming more comfortable. So far there are very few LCDs that actually implement the technology, the BenQ FP241WZ being one.
At Display Taiwan 2007, Chi Mei Optoelectronics (CMO) introduced yet another method ("Clear Motion") to reduce ghosting effects. This algorithm sharpens the image as it moves, partially counteracting the blurring that accompanies moving pictures on an LCD. So far, the technology has not been implemented in any LCD monitor.
- Input Lag
Input lag is different from a high response time. With input lag the whole frame is delayed by a certain amount of time, causing a delayed response. It can be annoying in a situation where you expect a quick and smooth response (e.g. moving your mouse). If you're watching a movie it may not even be an issue since no particular response is anticipated. In games there will always be a disadvantage since you won't see your opponent quite as fast as he'll see you (if he uses a faster display). Graphics design may also present a problem (the resizing of a circle may take longer to actually register on screen). I can not tell you how bad input lag is, because it's a matter of sensitivity. You may want to use the bigger screens (23"+) at the store, if they have them hooked up, to judge whether or not it annoys you. It's most likely to affect you if you do activities on the PC that are sensitive to timing, like gaming or audio processing.
Input lag is thought to be caused by the frame buffer kept in an LCD for advanced operations like adaptive contrast and overdrive. This frame buffer usually needs to contain 2-4 frames to do its work effectively. 2-4 frames * (1000 ms/60 Hz) = 33 ms - 67 ms. of input lag at a 60 Hz refresh rate. Still, the amount of input lag depends on the image transition that is occurring, and as it stands the "frame buffer" theory has no way of explaining why it varies.
The amount of measured (min - avg - max), or estimated (avg), image delay is provided for each LCD in the Recommendations section. (Credit goes to DigitalVersus for the input delay data.) Please note that all measurements mentioned here of image delay are input lag plus the response time it takes to show a digital timer's number segments on the LCD. (The response time it takes to show the segments (usually strict black->red transition) is very short, so image delay is not an accurate measurement. It serves only to help you compare what you'll experience among different LCDs, which it is quite accurate for.)
VA panels are typically high in input lag, however there have been a couple instances of very little to zero milliseconds of input lag. It is still unknown what causes input lag.
- Dynamic Contrast/Color
There are a couple reasons that manufacturers have created these technologies. With dynamic contrast (or "ACC"), lowering the brightness when it's not needed can save power and improve the black level at the same time. It also gives vendors yet another way of inflating their specifications, by stating a higher contrast. This "dynamic contrast" value is generally the black level at its lowest point and the white level at its highest point, neither of them necessarily in the same frame of video, which is why the spec is a fallacy. Still, the technology is actually pretty useful for movies and perhaps games. For general usage, it's not really feasible as the brightness fluctuation is too easily visible.
There are also algorithms that adjust gamma depending on the scene shown, often called "DV modes" (NEC), "MagicColor" (Samsung), or "image modes" (Dell). These algorithms claim to "preserve" skin tones and make the picture more natural, but generally they just oversaturate the picture. Most of the time, switching them to the "Standard", "Desktop", or "Off" modes and performing rudimentary calibration of your monitor yields the best results. You should never use the modes with calibrated settings.
Chi Mei Optoelectronics has also developed a method of expanding the monitor's gamut on-the-fly by adjusting LED backlights, but it'll be awhile until this is implemented in desktop monitors.
- Dead Pixels
Dead pixels are pixels that are not functioning properly. They will appear as a dot on the screen that doesn't update, so they will be stuck to one particular color (usually black or white). Dead pixels are usually caused by the driving transistor of the pixel in question dying. Occasionally only a subpixel dies and you get other colorful types of dead pixels. You may be able to "revive" them by using software that flickers at the spot of the dead pixel, but be aware that this could cause more dead pixels to appear.
Dual- or multi-domain panels such as S-IPS and MVA can have halves, quarters, or eighths of a dead pixel since one cell out of the 2, 4, or 8 that make up a subpixel died.
Policies can vary, but most manufacturers have fairly lax (in their favor) rules when it comes to dead pixels, such as the common eight-dead-pixel policy. If you get really lucky, you may find "no tolerance" policies on some LCDs (or laptops).
A list of policies is available in this BeHardware article.
Tips and details on how to fix dead pixels are available here: Wikihow - Stuck Pixels.
- Viewing Angle
The limited viewing angle of LCDs is due to their physical properties. In a TN, crystals are aligned like a big helix that twists to control light output. The problem is, when you move your head, they appear to be in a different orientation since you're looking at the cell from a different angle.
VA-type panels generally contain four or eight domains of cells, so they're kind of like a brute force solution to the problem: just add more cells and adjust them to appear the right way in every direction. There are far more fundamental differences between TN and VA panels, but this is what makes the VA panel's viewing angle so wide.
IPS panels have crystals that tilt in-plane, so the image appears to be more or less the same in all directions. Newer dual-domain IPS panels such as DD-IPS, or S-IPS, are still as good.
The viewing angle measurement should state the angle at which you can view a relatively clear picture, although manufacturers often test with a minimum of 5:1 contrast for TN and 10:1 for VA and IPS panels. On TN panels, there will be some fading and color shift. There will always be complete inversion when viewed from a bottom angle. VAs will wash out in all directions with a slight tint, and with lower quality VA panels the grayscale can get yellow. IPS panels simply fade in brightness a little, with absolutely no grayscale inversion, so they are considered top-of-the-line in this category. The only caveat of IPS panels is that from an extreme diagonal direction, black can turn a quite obviously violet color. Since you have to look at such an odd angle, this generally is no issue for the user.
- Ergonomics
Some LCDs have pivot, rotate, tilt, and height adjustment capabilities. Pivot allows you to go into "landscape" or "portrait" mode (e.g. 1050x1680 resolution instead of 1680x1050). This can be convenient for working on tall documents or browsing web pages. Sometimes you have to manually tell the graphics card to rotate the screen, but newer LCDs have a feature where the graphics card is notified of the physical rotation and the new resolution is automatically set. The panel of many LCDs can also be rotated along the X axis and tilted on the Z axis.
- Refresh Rate
Current knowledge indicates that LCDs are internally synchronized to a refresh rate of 60 Hz. That means that whatever's coming out of the DSP (scaler) must be 60 Hz. Many scalers are able to use frame rate control to convert a 75 Hz signal to a 60 Hz one, although this can cause the image to jitter. For your sake, it's advised that you leave your refresh rate to 60 Hz if you experience any of this. If the frame rate conversion is great and the image does seem smoother, then there's no reason to go back to 60 Hz. Using a refresh rate higher generally shouldn't damage the LCD; the DSP will simply reject or convert refresh rates out of range.
LCDs like the Samsung 970P lack an "overdrive lookup table", so they experience increased response time when dealing with higher refresh rates. This limitation is rare, and in fact the 970P is the only case I know of. TFT Central has more details on the 970P.
III. Multimedia LCDs/Input Options
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- Audio/Integrated Speakers
Integrated speakers are fairly common in monitors marketed as multimedia/multifunctional. Although these speakers (generally 1-5W) will suffice, you'd generally want to use better, external speakers. Most of these monitors have jacks so that you can hookup external speakers or headphones.
Audio inputs are also available, allowing you to feed composite audio to the internal or external speakers.
- TV Tuner
Some monitors such as the NEC 20WMGX2 have a built-in analog TV tuner. There are currently no desktop LCD monitors available with a built-in HDTV tuner, however, so you'd have to hookup an external one if you wanted to watch HDTV.
- Video Inputs
Many LCDs come with both a DVI (digital visual interface) and VGA (video graphics array) interface. Due to its digital nature, DVI will always deliver a perfect picture. VGA, or analog, can sometimes appear noisy or blurry on an LCD. Generally the difference is insignificant with a powerful RAMDAC (digital->analog converter on the video card) and a good analog input on the LCD. In a lot of cases VGA can look as good as DVI on an LCD, especially with resolutions 1680x1050 or lower. Laptops, however, are notorious for having weak VGA outputs.
Multimedia LCDs may even feature HDMI (arbitrary-bandwidth digital video and audio interface), component (YPbPr), S-Video, composite (Y/C) inputs. These are typically paired with PIP (picture-in-picture) and/or PBP (picture-by-picture).
Video quality ranking (1 is best):
Digital- HDMI (165 MHz+)
- Dual-link DVI (310 MHz)
- Single-link DVI (165 MHz)
All digital connections provide the same quality picture, if they all operate at a sufficient bandwidth. HDMI and dual-link DVI can reach higher resolutions and refresh rates than single-link DVI (which can cause image degradation at higher bandwidth (resolution * refresh rate)). Lower quality DVI transmitters and cables have been known to result in pixels appearing to be dead or image noise/jittering.
Analog- VGA (~350+ MHz@-3 dB)
- Component
- SCART
- S-Video
- Composite
Analog connections can carry an infinite resolution and refresh rate but also decrease with quality at higher bandwidth. Thus, the image is never 100% perfect but it can be more than ideal.
- HDCP
HDCP stands for high-bandwidth digital content protection, a scheme developed by the movie industry. It will be mandatory for playing Blu-Ray/HD-DVD discs with the HDCP flag set, on any PC operating system or set-top box. It is not required for everyday usage of Windows Vista (nor its Aero function) although the same rules apply for playing Hi-Def discs. HDCP can be implemented on the DVI port or HDMI port. It may be something to consider if you want to play movies on your monitor, but not even all discs or programs require it. Note that HDCP support is indicated under each monitor recommended in this post.
IV. Specifications
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- Size: This specification most frequently refers to the "viewable size" of an LCD panel, the diagonal size of the panel that is active. In a few cases, 25.5" monitors are actually labeled as 26" ones instead. Usually, the bigger the monitor the higher the resolution.
- Pixel Pitch/Dot Pitch: Dot pitch is the size (mm) of any given pixel on the matrix. Rarely do the width and height every vary (i.e. non-square pixels). Smaller dot pitches will provide a more fine picture with more accurate/sharp fonts. AA (antialiasing) and scaling will work better with a smaller dot pitch. It will also makes fonts appear smaller unless you use compensate with the rather shaky Windows DPI settings (they screw up a lot of dialogs). A larger dot pitch will give you bigger and slightly less sharp fonts along with bigger images. Those with eye trouble are generally advised to use the bigger dot pitch displays since the overall image is easier to see.
- Native Resolution: This is the resolution for which the LCD matrix was developed. Use of any other resolution will result in the need for digital scaling, and a downgraded (sometimes blurry or chunky) picture.
- Brightness: This is a typically more accurate spec. This value should be the white level at its brightest setting. This does not mean, however, that the monitor can show all shades of gray as the crystals may not be able to shutter light accurately at this brightness level. In reality, it just states the backlight's brightest setting.
- Contrast Ratio: This is a spec you should probably ignore, because it's often inflated (especially with TN panels). Although, extremes can indicate a difference in panel technology, or that one panel has dynamic contrast. A dynamic contrast measurement is sometimes denoted with the "(DC)" suffix or "DFC" prefix. Some manufacturers offer real and dynamic contrast figures, both of which are usually inflated.
The formal definition of contrast is the ratio of the white level over the black level.
- Viewing Angle: Although the spec itself has been marred with inaccurate values, you can still get an indication of the panel type from this value. Panels that state 170/170 degrees or lower are always TNs (this can actually get as accurate as 140/135). LCDs that claim 176/176 or 178/178 at 10:1 contrast are VA or IPS panels. If 176/176 or 178/178 is a measurement at 5:1, the panel can be a TN! (See NEC LCD24WMCX and Eizo S2201W.) Panel type can be further confirmed by using panel search sites and general vendor/panel use trends.
- Response Time: This was described quite accurately farther above, but the spec itself simply can not be trusted at all. One useful tidbit: panels that state a gtg or g2g (gray-to-gray) spec often employ response time acceleration. Previously the only way of measuring response time was the less accurate "rise and fall" (Tr+Tf), or "black-white-black" (bwb), method. Usually this meant measuring the time it took for the crystals to change from 10% light to 90%, and back down to 10% brightness. The more-realistic gray-to-gray method usually involves taking the average of five steps of intermediate color transition times. Gray-to-gray is a better way of measuring response time since it comprises the majority of image transitions in real life (gradual, not extreme like "bwb"). That doesn't mean the g2g measurement as stated by manufacturers is any more accurate, though.
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V. Recommendations
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- Please see Post II (below this post).
VI. Using Your LCD
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A. Calibration
The best way to adjust a monitor is to use a colorimeter, of course, if one is available. Recommended colorimeters include the Gretag-Macbeth or Pantone Eye One Display 2, aka "i1 Display 2" (each manufacturer = same hardware/different software). The Spyder2 Pro is almost as good as the last two, but probably not worth the price since you can get an i1 Display 2. The Spyder2 Express is at the lower bound for calibration. Some less expensive colorimeters, like the Pantone Huey, just aren't worth it and may actually have a detrimental effect on some colors. The Huey Pro, however, is quite a viable option and a good value. [1] The Monaco Optix XR is the best colorimeter but can run you a lot of money and it's probably not worth it over the i1 Display 2.
Calibrating a wide gamut display may require different or newer versions of calibration software. Cheaper colorimeters may have more of a challenge with wide gamut displays, if any wide gamut calibration software even supports them.
If you do not have a colorimeter, you may be able to obtain a premade ICC profile from the Monitor Profiles/Settings Thread or from the HardForum Calibration Thread. In the first thread, only a few have been calibrating using a colorimeter, and those are noted accordingly. Instructions on how to apply the profiles are also available in those threads. For Windows, the Microsoft Color Control Panel Applet for XP is the best way to apply a profile. In Vista, this control panel is included.
DigitalVersus calibration profile guide and database: http://www.digitalversus.com/article-424.html
If a colorimeter-made profile is unavailable, then here's the next best way:
1. Clear all software and video card gamma correction values (all should be = 1.00 or default).
2. Use the standard/general "Image Mode" (Dell) or "DV Mode" (NEC) for general PC use. Samsung's "Magic Color" should be in the off state.
3. Adjust the brightness and contrast to something comfortable. Usually you want a higher contrast and lower brightness with LCD monitors. A high brightness causes a higher black level. It's preferable you instead exploit your LCD's high contrast by adjusting "contrast". This will need to be a value low enough that it doesn't burn the end of a grayscale gradient. It's easy to tell when this is happening if you just load up a grayscale. Find a value that is comfortable for you and doesn't clip the grayscale. Some Dells only have a brightness setting but you should be able to find something acceptable to satisfy those criteria.
4. Load up a pure white image. Use "user settings" for your monitor. Adjust R, G, and B until the white looks natural to you. Note that contrast is a secondary adjustment of R, G, B values (it sets a bias to them), so these settings kind of go hand-in-hand. A too high value of either contrast or the R/G/B components will cause burning at the end of the grayscale, not something you want.
You can also try mg2plus's calibration guide here: http://www.galacticmag.com/mon...ness-and-contrast.html
The safest and neatest way of cleaning any LCD is to use distilled (soft) water with a microfiber/soft cloth. Remember to turn off the LCD before you attempt cleaning.
Products like Monster Cleaner can work for standard anti-glare coating LCDs, but it is recommended not to use anything other than water for glossy panels due to their fragile coating. Your risk of damage to any LCD panel is much greater when you use anything but water. Usually, it's also needless since a good water/cloth cleaning will look great. Ammonia-based cleaners are the worst thing you can use to clean an LCD, short of sandpaper. Alcohol-based ones may work but their use is certainly not encouraged either over the standard water/cloth combo. They have also been known to damage LCD coatings.
Applying gentle pressure is always something to keep in mind when cleaning an LCD. Although pressing a medium amount generally can't hurt them, don't treat them the same way as furniture.
CRTs without a special coating may benefit from the stronger cleaners since they are made of glass, but CRTs with OptiClear coating can be damaged just as well when using anything except water.
The general consensus is to use alcohol-based cleaners only when needed, to remove oils or fingerprints. Continued use can cause problems. See this site for more info: http://stanxterm.aecom.yu.edu/...w_to_clean_LCD_screens
In my personal experience, I have cleaned a 20WMGX2 (glossy) with 91% isopropyl (rubbing) alcohol with no trouble. I have done the same for the LCD2690WUXi (matte) without a problem. The glossy panel hadn't been cleaned with anything except water in years, and it was getting very difficult to clean with water only. The matte display suffered from a masking tape accident, although the isopropyl alcohol got rid of the stickiness just fine when water seemed hopeless. I noticed no degradation of image quality in any aspect after fully cleaning both screens with rubbing alcohol, but please, be careful of your LCDs!
Appendix A. A Few Words About "Panel Lotteries"
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Several manufacturers, including Dell and Samsung, have played the panel "bait and switch" game thinking no one would notice. A controversial practice called a "panel lottery" by others, they will originally release a good panel (for reviewers) and switch to an inferior one later on. Dell first put an S-IPS in their 2007WFP and later switched to an S-PVA, whose performance was deemed very low compared to the S-IPS. Samsung originally was making "S" (Samsung) TN panels for their 226BW, until they outsourced their production to AU Optronics ("A"), CMO ("C"), and CPT ("P"). The A, C, and P panels performed poorly at the default color settings. All of their colors were equal after calibration, although the C panel had more issues with response time. Since many folks don't own a colorimeter, they will end up with a panel that can't display colors with the same fidelity as the original "S" panel. Later, both Dell and Samsung began hiding the panel information from the service menu and the back panel.
In an interview, Samsung stated that after April 1st they would release only "S" panels (in France). Three Frenchmen discovered 2 A panels and 1 C panel with their 226BWs manufactured after April 1.
Dell and Samsung claim that they did this because of stock problems. Well, if they didn't have enough stock why did they continue selling it under the same model name? It obviously makes it frustrating for users who try to pick the right panel. It doesn't help that the "alternate panel" often falls way behind the original.
HP also has switched to AMVA in its HP LP2065 model in some cases, but at least they registered the change with the FCC in publicly available format unlike Dell/Samsung who really kept it under the covers. HP did keep a label on their box also indicating the panel.
The main purpose of this section was to raise awareness of this problem, and hopefully send a message to the vendors involved that the panel switching needs to stop.
Update (10/10/2007): Unfortunately, nothing has changed since so I am back to recommending the monitors, simply because their alternate panels are still better than other LCDs.
Update (11/25/2007): Better LCDs have appeared since, so the 206BW and 226BW are gone. They both have response time problems, blue color hues, etc... Hopefully Samsung will change their mind for the better with the 2032BW and 2232BW. Samsung, use whatever panels you please, just make sure they all have roughly consistent performance.
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Appendix B. Additional Resources
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No review or resource can be 100% accurate, but these sites may help you in your buying decision.
- News/Wiki/Blog/Feeds
- Engadget Displays (good for new product announcements)
- DisplayBlog (great for industry news)
- DigiTimes Displays (in-depth look at the Taiwanese LCD industry)
- TFT Central (the "dark meat" of LCD news)
- TrustedReviews (lots of original news)
- Professional Reviews (in order of usefulness)
- X-Bit Labs (gold standard)
- Tom's Hardware Guide (extremely reliable)
THG Subsidiaries (often more frequently updated): - THG France (tomshardware.fr translated)
- THG Russia (thg.ru translated)
- THG Germany (tomshardware.de translated)
- BeHardware (English version of hardware.fr (very reliable))
- TFT Central (very reliable and awesome for news)
- prad.de (German and English) (very reliable)
- Bit-Tech (very reliable)
- ExtremeTech (very reliable)
- AnandTech (in-house) (very well-rounded and reliable)
- TrustedReviews (more subjective but certainly worth a look)
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