Colour Banding in Half Life 2?

[Recall]

This is something that has persisted through all my graphic cards ( ati / nvidia ) since the game came out. It is now very noticiable on my new high contrast LCD to the point of distraction.

Basically in dark areas I see green, purple, red. Like a rainbow effect almost. The current GPU I have is a 8800GTS. Can anyone give me an idea on what is causing this? I also notice it in fear, but to a much lesser degree.

Here is the FEAR screenie ( look at wall ) http://mnetcs.com/thumb/storage/b8083501.JPG

Here is the Half Life 2 screenie ( check the green step! )

 

[AlphaWolf]

hrm those shots are so dark for me I can't see much of anything.

 

[AlNom]

I see some green and pink on the far wall at the top of the stairs... that's about it. Texture compression or low precision

 

[Recall]

I see some green and pink on the far wall at the top of the stairs... that's about it. Texture compression or low precision

Yeah, this is the bits I am on about. It does seem like low precisions doesn't it?

Guys, you need to really turn up the contrast and brightness to see what I mean.

 

[Skrying]

Yeah, this is the bits I am on about. It does seem like low precisions doesn't it?

Guys, you need to really turn up the contrast and brightness to see what I mean.

Crank the brightness? My monitor is already way to bright but if I take it down one more notch is a sharp drop off... Anyway, its clear in the FEAR shot on the window and just from experience in Source engine games I know what you're talking about. Source engine has it very bad...

 

[Recall]

Crank the brightness? My monitor is already way to bright but if I take it down one more notch is a sharp drop off... Anyway, its clear in the FEAR shot on the window and just from experience in Source engine games I know what you're talking about. Source engine has it very bad...

Hehe Ok well I am glad you know what I am on about. I was looking for a technical explanation and also if there is a solution. Reason being is that it is very distracting seeing these multiple colours that should not be there.

 

[Andrew Lauritzen]

If you whip out your image editor, you'll notice that the color values are changing only by 1, so it's not an engine problem. What it means is that for your given monitor contrast/brightness 8-bits per component are insufficient to represent a smooth gradient.

First I'd suggest calibrating your monitor; in particular increasing the contrast and brightness sufficiently will make *anything* look "banded", however that's not a useful observation in and of itself. It's only a problem if the monitor is properly calibrated and yet still banding is clear. On my monitor it's all fairly dark and I can't see any terrible banding unless I'm really searching for it.

Secondly higher-precision color (10-bit per component) will certainly help if and when it becomes the norm.

It's almost certainly a monitor calibration issue though. Brightness, contrast and gamma all affect the intensity curve and if set improperly (or too aggressively) they will map the outgoing luminance of the pixels far too sharply resulting in "banding".

 

[Silent_Buddha]

What Andy said, you can bring out "banding" in any game if you adjust gamma too high, or even brightness and contrast too high.

A friend of mine is notorious for this. He always cranks the gamma WAY up so he can see in "dark" areas of a game. And then he complains that there's massive banding.

With that said other than some jpg artifacts, I don't see any trace of banding in that screenshot.

Regards,
SB

 

[Skrying]

Well that's a issue. For instance, I have to crank the gamma to max (on both my old CRT and new LCD) in Source engine games (more specifically HL2, HL2:EP1, and CS:S) in order for it not to be dead black. Its just out right annoying that in order to see I have to deal with these horrible banding issues everywhere. CS:S is nearly impossible to play with any skill if you can't pick up counter terrorist helmets in the dark areas...

Ironically the issue is a bit less on my 6-bit LCD than my CRT...

 

[Silent_Buddha]

Interesting, on both of my Dell monitors (2001 FP and 2405) I have to turn the brightness WAY down to achieve good color fidelity. Likewise with a few adjustments to gamma.

That screen you have is almost perfect on my screen. Almost pitch black for the majority of it with only the top being slighly well lighted from lightsource off screen.

I'd imagine Valve designers did this on purpose.

Although if you tend to play in a very bright room (open to sunlight for most of the day, or maybe 150 watt light bulbs) then it might be a bit too hard to see anything. I have to go through this around 4pm - 7pm currently as that's when the sun shines directly into the computer room. Makes it rather difficult to play dark games.

Regards,
SB

 

[Andrew Lauritzen]

Make sure to play with both gamma and brightness/contrast separately. Gamma is a power function, so it will behave differently with respect to spreading out luminance at different intensities.

I also have to turn my brightness down to 10 or so out of 100 or else my LCD is blindingly bright. The color reproduction is also much better at the lower setting.

I'd recommend going through a proper color setup tool such as the one in NVIDIA's drivers IIRC, or similar. Get the settings right in there, and then for the most part just leave them. If a game is too dark, the game designers might have done it that way intentionally... I didn't like Doom3 for the single purpose that I was only viewing 1/4 of my screen at any given time. Moody is one thing, but Doom3 is just *dark* I haven't had much trouble with HL2 though, excepting the portions which are supposed to be black (like the elevator bit in EP1 ).

 

[Skrying]

I'm talking more about dark corners and its probably a by product of my competitive playing CS:S. I just need to see everything or I feel like I'm being held back.

I'll test around a bit, but besides some games my image is beautiful.

 

[Jawed]

LCDs, notoriously, have their black level set way too high - it's a function of the technology. Then, it seems, they have the wrong gamma. This link will allow you to evaluate your gamma at a wide range of effective tones:

http://www.tsi.enst.fr/~brettel/TESTS/Gamma/Gamma.html

set the top slider anywhere (it's the target you'll be aiming for in a second) then adjust the bottom slider so that the two grey areas match and "merge" (sit back from your monitor and squint your eyes). The applet displays the gamma value your monitor is set to for that tonal value. Try a dark target, a medium target and a bright target.

This next link:

http://www.photoscientia.co.uk/Gamma.htm#menu

provides a quick and easy way to tweak all your settings. You should configure your system for gamma 2.2, so click on the gamma 2.2 option. You want to make all three sets of boxes as neutral as possible.

You do this by adjusting your control panel. This picture shows control panel for an imaginary LCD monitor (the curve, if I remember the numbers right, is approximately what I configured for a friend's Dell 2405, for what it's worth):

NOTE: the drop down there is set for Full Screen 3D. You first need to make settings for Desktop (otherwise you can't see any changes!). Once you've got settings that are correct according to Gamagic, then copy them over to your Full Screen 3D settings.

Notice that you must make the top right end of the line land precisely in the corner. It shouldn't take too long to tweak all three of these sliders so that the Gamagic boxes show as neutral. Think of it as a mini-game.

The NVidia control panel should allow you to do something similar.

This doesn't solve the problem of how to set in-game gamma/contrast/brightness sliders, sadly - try them on defaults or all set to "1" or "middle". If you're seeing banding then you've prolly got something "too bright".

Jawed

 

[Xmas]

It's unfortunate that there is still no driver option to force a 10 bit per channel framebuffer format for those cards that are able to output it to screen.

 

[Davros]

that would be a bit pointless on a lcd though

 

[Arnold Beckenbauer]

that would be a bit pointless on a lcd though

Why?

There is an option in DXTweaker to force A2RGB10 as backbuffer format (under Present Changer), but I have no idea, if it helps.

 

[Xmas]

that would be a bit pointless on a lcd though

You can dither on output if the output color resolution is the limit.

 

[LeGreg]

..my new high contrast LCD..

Well there you have your answer.
It's not the game(s) it's the LCD.

 

[Windfire]

This is something that has persisted through all my graphic cards ( ati / nvidia ) since the game came out. It is now very noticiable on my new high contrast LCD to the point of distraction.

Basically in dark areas I see green, purple, red. Like a rainbow effect almost. The current GPU I have is a 8800GTS. Can anyone give me an idea on what is causing this? I also notice it in fear, but to a much lesser degree.

I've experienced the same thing with my Dell 2405 with my 6800GT. It only occurs in some dark areas and the dark areas have dark colors are tinted red, green, etc. I always kind of assumed it was a driver optimization thing or something.

 

[swaaye]

Hook up a CRT and see it go away. I have a 2405 too. This banding is just the lacking color depth of the LCD. It can't reproduce nearly the same range of colors as a CRT, and in dark areas you see it much easier than other places. As far as I know there are no LCDs that will get rid of this.