Shadow Mask or Aperture Grille?

[GuildBoss]

Time to replace my ol' trusty 17" MAG. I've got my eye on the two following 19" monitors:

- iiyama i91A/Vision Master Pro452 ($339 delivered)

- Hitachi 771 ($~380 delivered)

Both appear to be about equal in price and scan performance but the biggest difference is the tube type--the iiyama uses a DiamondTron aperture grille tube while the Hitachi uses a shadow mask.

I've read good and bad of both types, ie the AG tube has two faint horizontal lines that can be seen but offers more vibrant colors while the SM tube is less vibrant but is still very sharp but doesn't have the lines.

So I'm looking for opinions of these monitors (and the tube types). Are those lines really *that* visible? Do they distract the eye? Are shadow masks as vibrant and sharp?

TIA!
Paul

 

[Gosharkss]

These are all general statements that in reality mean very little. You will get many responses from people who will tell you the lines on an aperture grill are hardly noticeable, then other will say the really bother them. Also it depends on the application you plan on using. They bother me because I use applications primarily white background with black text. If you are a game player or use dark backgrounds you will never see them. Bottom line is do the distract you? Maybe they will maybe not.

I never trust general statements like "aperture grill monitors are clearer and brighter the shadow mask monitors" or "shadow mask has sharper text". Every unit produced is unique and, like fingerprints, no two are identical. Even the highest quality monitors occasionally don't perform as promised.

The type of tube is only one aspect of monitor performance. The ability to display fine detail on a computer monitor involves many factors including luminance setting, geometric distortion and convergence. Convergence specifications IMHO are more important than the type of tube used. It determines how sharp the characters in your text document or spreadsheet look. Convergence has a direct effect on the monitor's apparent focus. Unfortunately, convergence or brightness are specifications that few manufacturers publish.

I recommend that you call and e-mail the technical support line of the manufacturer and reseller before you buy. First time how long it takes you to reach a human or an e-mail response and then ask them some questions about the monitor you are considering. You don't want to sit on hold; you want to talk to knowledgeable people. They aren't trained to "polish" the answers like sales reps might, and you'll get a sense for how technically competent and knowledgeable they are and how the company may treat you after the purchase.

Good Luck

Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com

 

[GuildBoss]

Thanks for the input.

I'm the type of person that will be bothered by the lines if they're obvious but since this monitor is going to be used primarily for gaming and most certainly games do have darker backgrounds, it may not be an issue.

I've yet to see either of these monitors in any local shops but even so, I've never seen any lines on Sony monitors or others that use some type of Trinitron tube. *shrugs*

I'm leaning toward the iiyama. I've heard pretty good things about iiyama's customer service, that they'll go the extra mile to keep their customers happy. If I see lines and they bother me I suppose I'll just send it back.

 

[Kingofcomputer]

since you've already looked at both,
buy the one you like more,
or buy the one with higher spec,
or buy the cheaper one if you're on budget.

 

[duragezic]

<< I've read good and bad of both types, ie the AG tube has two faint horizontal lines that can be seen but offers more vibrant colors while the SM tube is less vibrant but is still very sharp but doesn't have the lines. >>



Although those are people's opinions, MOST will agree that is true, especially that a AG monitor has brighter colors.

For me, I'm with that. AG's have better colors than a SM. The whole text sharpness... I find that SM only a TINY bit better quality. So when I don't consider that a disadvantage for a AG though it's all about personal preference.

Personally, I'd get the iiyama. Definitely one of the best to get if you do get a 19&quot; AG. If you're gaming mostly, you won't even notice the lines like you said.

And for me, until I read a post asking about AG lines, I don't even notice them in windows. It's not they are hard to see, I just don't care if there is a faint grey line that goes across the screen.

 

[Gosharkss]

eagle_2


<<

<<
For me, I'm with that. AG's have better colors than a SM. The whole text sharpness... I find that SM only a TINY bit better quality. >>




How do you quantify that statement. What evidence can you produce to back up these claims? I could argue that some SM have better colors than AG. The electronics driving the CRT (Video Amp) for example have a major impact on color quality and brightness. Again these general statements in the real world are meaningless without data to back them up.

Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com

 

[sandorski]

I'll probably never but a SM, I much prefer AG. Just looks better to me.

 

[duragezic]

Gosharkss:

Well I meant to say that it is just my opinion. Just my opinion that SM has hardly noticeably better text quality.

Monitors are very controversial. You know that yourself. I just wanted to add that because hey it might turn out someone has the same views as me.

 

[GuildBoss]

One last question. I noticed in another thread someone mentioned the iiyama has a low video bandwidth (it's 160 mhz). Does it make a difference? The refresh rates are good, so what difference does the overall bandwidth make, if any?

FYI, the Hitachi has just over 200 mhz bandwidth...

TIA

 

[vlieps]

I have a little different opinion about Trinitrons/Diamondtrons (AG).
At work I had like 5 Sony 21'' monitors and a couple of high-end SM monitors, also 21'' (Hitachi actually, I do not remember the model numbers). I agree that the colour is brighter on AG, but I was not the only one who said they ARE NOT SHARP. And that is actually more noticeable than the brightness of the colour.
At least in my case the SM was much better than AG. I have heard that from other people as well. You might want to check out yourself, just to be completely sure.
Black text on a white background is the best to see how sharp each monitor is. Do not bee fooled by some video clip or game or something like this. Good luck. I would go with SM.

 

[Eug]

Depends on what you like, but like the others make sure you sit there and type in Word or something for a while before you decide.

I use both, and in the same price range I TEND to like shadow mask better, partially because I do a lot of stuff using text (Word, Excel, etc.). Plus, I find the aperture grill lines irritating in Photoshop. (Then again, some people around here haven't ever even seen them.)

 

[Gosharkss]

GuildBoss

Bandwidth is a little complicated and needs some explanation and background in monitor technology.

There are three components that make up the monitors refresh rate. Bandwidth, horizontal scan rate, and the vertical scan rate or &quot;refresh rate&quot;. They are all interrelated.

Monitors draw pixels on the screen one at a time starting in the upper left corner across the screen, then down one line and so on. The time it takes to draw one pixel on the screen is commonly called the video rate, pixel clock or bandwidth. The time it takes to draw one line across the screen is the horizontal scan frequency. Finally the time it takes to draw one complete field &quot;entire screen&quot; is the refresh rate.

Basically, the faster you can draw one pixel on the screen, the faster you can draw a line across the screen, the faster you can refresh the screen.

If your monitor does not have sufficient bandwidth, this will limit the maximum refresh rate and resolution that can be displayed. Almost all monitors on the market today have bandwidth specifications that are sufficient for the resolution the manufacturer recommends. But be careful out there. I see some manufacturers that publish the maximum resolution in BOLD print and the recommended resolution is small print. What they are saying is. Yes the monitor will display at that &quot;BOLD FACE RESOLUTION&quot; however the bandwidth of the monitor is really optimized for the lower &quot;recommended&quot; resolution&quot;.


&quot;Bandwidth&quot; is the range of video frequencies that can be adequately handled by the video amplifier of the monitor. However, there are so many different ways of measuring the &quot;bandwidth&quot; of the video amp - some relevant, and some not. Without knowing how the manufacturer measured the bandwidth it may not be a very useful specification for comparison purposes.

I prefer to use the video amplifier rise/fall time specs, as measured at the cathode of the CRT between the 10% and 90% points on a full-swing, &quot;white to black&quot; signal. Obviously, you want this time to be somewhat less than a pixel time; something like 1/3 to 1/2 of a pixel time is reasonable as an absolute minimum-acceptable spec. (Shorter rise/fall times are better, but only if they can be achieved without &quot;ringing&quot; or other problems - like excessive RFI.)

Also I agree with the last two posters. When most people talk about shadow mask they remember the old 14 Inch fishbowl designes. Take a look at the modern shadow mask monitors and you will see what I mean, big improvment.

Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com

 

[Playmaker]

Guildboss, where did you find the iiyama for that price shipped? I think I want to buy one, but most places are more expensive then that with shipping.

 

[OllO]

Please excuse me for jumping into this thread with a different, but somewhat related question, but I feel this is the place to ask

I have heard that the dot pitch is what limits resolution in an sence, but that you can at times have a higher rez then what the dot pitch would normally allow. For instance, tha mask of a .28 (forgot what unit) dot pitch monitor has a certain maximum rez, and if you exceed it the output wont be as sharp, since more than one pixel would have to be in each &quot;hole&quot; in the mask. My question is: What are the different true max resolutions for the various dot pitches (I have a .28, so that is what I'm most interested in )?

Thanks,
OllO

 

[Gosharkss]

In terms of a monitor there really is no concept of a pixel. Monochrome monitors did not have a mask structure. They used a single beam and no mask structure. The entire inside face of the CRT was coated in phosphor. From the monitors point of view the pixel was defined for the most part as the size of the electron beam. Same concept in a color monitor, only you have three beams and a mask to ensure the correct beam hits the correct color phosphor. For all the monitor cares, the video card could be building each line out of millions of active logical pixels. I like to think of a logical pixel as the speed thee video card modulate the beam, this determines beam size.

The number of the holes in the mask and stripes in the aperture grill technically set the maximum resolution of the monitor. At lower resolutions the logical pixels simply cover more than one hole or slot. The logical pixels do not need to line up with the physical holes or slots nor is there any mechanism to do so.

At resolutions that exceed the number of holes or slots across the screen, logical pixels (electron beam size) no longer hit the phosphors accurately enough to guarantee constant colors or luminance. Some of the beam is intercepted by the mask structure. On monitors with lower horizontal dot / aperture pitch, more of the beam is intercepted by the mask. However an image will still be displayed and in practice will look OK.

I find it is best to run at a minimum of 85Hz-refresh rate and resolutions just below the maximum number of holes or slots in the mask to keep accurate colors and luminance. This is easy to calculate.

For example: A 21&quot; monitor typically has a horizontal viewable area of 395mm. Let's assume it has a 0.22mm horizontal dot pitch. 395 * 0.22 = 1795 dots across the screen. A monitor with the same viewable area and a 0.24mm horizontal dot / aperture pitch has 1645. This is one reason 1600 horizontal resolution is so popular.

Vertically is not so much a problem. A typical 21&quot; monitor has a vertical viewable area of 295mm. Aperture grill monitors have a 0.00mm vertical aperture pitch. Vertical resolution capability is virtually unlimited. As with every technology the trade off is more beam current hitting the phosphor making them more susceptible to screen burn. Use a screen saver!

Most shadow mask monitors have a 0.14mm vertical dot pitch. 295 / 0.14 = 2107 lines far more than any video card can produce at any decent refresh rate.

Good question. I hope this helps

Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com

 

[OllO]

That was just the answear I was looking for, Jim. Thanks! In fact, I will copy and paste this to Word and save a copy.

OllO

 

[LuciferHaze]

You want an Aperture Grill monitor as it has better and brighter color consistency but they generally cost more than Shadow Mask.

 

[Kingofcomputer]

I prefer Shadow Mask:
better and sharper text consistency
less bowing border
costs less than Aperture Grille

also check out new flat shadow mask/shadow-flat mask.