Samsung 193p+

[BearOso]

I recently purchased a Samsung 193p+ LCD monitor. I noticed that the monitor dithers some colors, particularly shades of gray. I've only ever owned 6-bit panels in the past, so I'm not sure whether this is normal for the monitor in particular, i.e. related to color-correction or something similar.

Samsung's website claims it displays 16.7M colors as opposed to 16.2M, so I'm assuming that the monitor is SUPPOSED to have an 8-bit panel. Can anyone else with this monitor (or other 8-bit panels) confirm the same issue?

 

[xtknight]

16.7M can also mean 6-bit.

 

[Unkno]

i heard it's 8-bit, not entirely sure though, try google

 

[ChuckHsiao]

Try seeing if you can tell the difference between the whites here:

http://www.amptron.com/chuck/bittest.bmp

If you can, then you have an 8-bit panel. If 252 and 255 both look the same, then you have a 6-bit panel.

It might be hard to see the difference between those shades though. Try setting the contrast to 100, and the brightness to various amounts. Also, try setting one of the squares to 251 first so you know how little of a difference you're looking for. You should see the boundaries between the squares if you have an 8-bit panel.

 

[BearOso]

Ok, I looked at the bittest image and I can see the difference between 255 and 252. But I can also see the difference on my 6-bit laptop display. What primarily concerns me is the dithering in the darker ranges of colors. Looking at the following images:
http://www.cs.iastate.edu/~bearoso/Dither.png
and
http://www.cs.iastate.edu/~bearoso/smt3.png
I can see noticeable dithering that is not inherent to the original images.

I referred to the 16.7M colors versus 16.2, as that seems to be Samsung's way of designating the display depth.

 

[BearOso]

I should probably add that changing the brightness and contrast settings also alter the dithering methods, which leads me to believe that the panel is restructuring the display output to change its characteristics instead of changing the backlight voltage/intensity too.

So could it be that these display panels, disregarding brightness and contrast adjustment have only 256 states per subpixel; with the adjustments have fewer? And they just map the input to a particular range of values depending on the monitor's parameters?

 

[ChuckHsiao]

Whoa you can see the difference between 252 and 255 on your 6-bit laptop? Funky, maybe they've found a way to overcome the 0-252 limitation of 6-bit monitors. I could think of some simple ways (for example, having 3 areas where they interpolate to 5 values instead of 4, so 0 and 5 interpolate 1,2,3,4 instead of 0 and 4 interpolating 1,2,3) but hadn't seen any show up.

That you see dithering at all tends to imply a 6-bit monitor, since 8-bit monitors don't need to dither to generate the in-between values, that is, 1, 2, 3, 5, 6, 7, etc. since 6-bit monitors go by 0, 4, 8, etc. (and hence the 0-252 limitation).

I'm surprised that it may be changing the brightness by using the LCD portion instead of the backlight. Doing so means that the LCD portion is only operating in a smaller range of values, cutting into its contrast and so forth. Maybe you could try setting it to 100 brightness and contrast and (after putting on sunglasses) seeing if the 1, 2, 3 portions are dithered nor not?

 

[Intelia]

I have te same LCD its 8 bit and have none of the problems you have. Also didn't your monitor come with information packet. MINE is not the+ model maybe that should read 193P- . Just kidding LOL

 

[BearOso]

I've looked into the issue some more and discovered that 8-bit displays do implement range subsets for color correction, hence the existence of "10-bit gamma" on some newer panels.

Chuck, you're probably correct on the boundary difference. It is ONLY 252 that is darker, 253-255 are identical on the 6-bit laptop. On this monitor, I can tell the difference between all the shades, even 255 and 254. The strange thing is, my laptop doesn't dither at all, leaving distinct color-banding in gradients.

Intelia, did you try looking at the two links I posted, particularly the second one? Look for a stippling effect within each band of the grey gradients.

 

[cockeyed]

DL TftTest , it has some good patterns to check for dithering effects. Use the arrow keys to change pattern colors etc.. I run it on my Acer AL1912 - 19" LCD (listed as 16.7m colors) and the patterns all look real good to me. If there is dithering, I don't see it and the colors have smooth transitions. I would think that your high end 193P+ would perform as good or better than my Acer.

I'm not in the market for a new LCD, but if I were, I would have had the 193P+ at the top of my list. From what I read about it, I thought it is an 8-bit LCD. I was surprised to read about your seeing dithering. Don't take offense, but have you checked your video card settings for 32-bit color, video cable connection, etc.?

 

[JRW]

Originally posted by: BearOso
Ok, I looked at the bittest image and I can see the difference between 255 and 252. But I can also see the difference on my 6-bit laptop display. What primarily concerns me is the dithering in the darker ranges of colors. Looking at the following images:
http://www.cs.iastate.edu/~bearoso/Dither.png
and
http://www.cs.iastate.edu/~bearoso/smt3.png
I can see noticeable dithering that is not inherent to the original images.

I referred to the 16.7M colors versus 16.2, as that seems to be Samsung's way of designating the display depth.

I see no dithering at all on those links on my CRT, I do remember my 2001FP showed dithering on certain images (Banding effect rather than a smooth transition of color) I just figured all LCDs were like this.

 

[Intelia]

I looked I see it just fine

 

[BearOso]

Originally posted by: cockeyed
DL TftTest , it has some good patterns to check for dithering effects. Use the arrow keys to change pattern colors etc.. I run it on my Acer AL1912 - 19" LCD (listed as 16.7m colors) and the patterns all look real good to me. If there is dithering, I don't see it and the colors have smooth transitions. I would think that your high end 193P+ would perform as good or better than my Acer.

I'm not in the market for a new LCD, but if I were, I would have had the 193P+ at the top of my list. From what I read about it, I thought it is an 8-bit LCD. I was surprised to read about your seeing dithering. Don't take offense, but have you checked your video card settings for 32-bit color, video cable connection, etc.?

I dropped down to Windows to run the tfttest program, and yes, there is noticeable banding. I also noticed the second image I posted actually has banding in Windows, same brightness and contrast, when in Linux it just has dithering. What mystifies me, however, is that you don't see dithering on the Acer 1912, which is a TN-film, 6-bit panel.

I see no dithering at all on those links on my CRT, I do remember my 2001FP showed dithering on certain images (Banding effect rather than a smooth transition of color) I just figured all LCDs were like this.

Ok, the 2001FP uses an LG SIPS display that has 8-bit color, and if yours has banding, then there's a little more evidence that I'm not crazy. I'm also using a CRT as a reference for this.

Intelia, can you tell me if whites/greys on your display look a little yellow at extreme angles?

 

[Intelia]

Here's what I see

255 white
254 offwhite
253 light gray
252 gray

At extreme angles no yellowing just not as much light

 

[BearOso]

Originally posted by: BearOso
I dropped down to Windows to run the tfttest program, and yes, there is noticeable banding. I also noticed the second image I posted actually has banding in Windows, same brightness and contrast, when in Linux it just has dithering. What mystifies me, however, is that you don't see dithering on the Acer 1912, which is a TN-film, 6-bit panel.

Ok, I see now that the Acer 1912 is a MVA panel, not a TN-film.

 

[BearOso]

Thanks Intelia, I'm pretty sure now that I've been screwed over.

http://www.sequoyahcomputer.com/Monitors/monitors.htm

According to this TN film panels have yellowish tints at off angles. Combined with the inexplicable dithering, I'm sure I somehow ended up with a TN panel. I've decided to return the display. I sure as hell didn't pay a premium for this.

 

[Intelia]

Get the 193p no ghosting in Games or DVD moveis $599. THAN a $200 rebate New Egg

According to what I have read yours should not be a TN film . Mine is a 20ms but would be equal to a 10 ms grey to grey. Yours s measured at 8 ms grey to grey one way =16 ms

 

[BearOso]

I read the same things, thus why I bought it. The only reason I can think of why this isn't the same would be because Samsung couldn't get the "overdrive" technology to work correctly, and defaulted back to a TN panel. Even now, trying google, no one has commented on display depth, but I HAVE read some reviews that the overdrive panels were overshooting the target voltages and producing bad results.

In this display, I can actually see the dithering patterns, which differ from what I would think they should be, so I can be sure it's not my imagination.

The LCD uses the following dithering patterns:
http://www.cs.iastate.edu/~bearoso/LCD_Dither.png

while I would expect this:
http://www.cs.iastate.edu/~bearoso/Standard_Dither.png

 

[cockeyed]

Originally posted by: BearOso

Originally posted by: BearOso
I dropped down to Windows to run the tfttest program, and yes, there is noticeable banding. I also noticed the second image I posted actually has banding in Windows, same brightness and contrast, when in Linux it just has dithering. What mystifies me, however, is that you don't see dithering on the Acer 1912, which is a TN-film, 6-bit panel.

Ok, I see now that the Acer 1912 is a MVA panel, not a TN-film.

It is my understanding that the Acer 1912 uses a TN or TN+ film. I've found sites that have it listed as one or the other. Whatever it is, it produces a real good image. Colors, contrast, brightness are all good and color transitions on the various test patterns are smooth. For the money, its a real nice LCD even though it has no DVI input. It is disappointing to hear your experience with the 193P+; I had the impression that it is one of the best LCD's. Hope you have better luck with your next one.