X1800/7800gt AA comparisons

[Ailuros]

I would like to remind that you shouldn't ignore the fact that you are looking at screenshots and on obviously different monitors with varying display resolutions.

I'm not saying that you can't judge up to a certain degree image quality based on screenshots, but one should keep a few more factors like above in mind.

I see Sharkster posted in the meantime that does point partially in that direction

Shark,

Gamma correction can also be enabled on the G70, yet it will only do you good on both accelerators if the presupposed gamma value is being kept. Most sites show fence shots from HL2; it's somewhat silly in a way because you can play that game in 1600 with 4xAA/16xAF and add adaptive or TSAA on either/or accelerator (yes even optional gamma correction on the G70) and still be way over the 90 fps ballpark.

 

[DemoCoder]

Huh? Most CRTs have superior contrast ratio to LCDs.

 

[Skrying]

Huh? Most CRTs have superior contrast ratio to LCDs.

Yes, I dont know any proof, but I've always heard of CRTs having higher contrast ratios than on all LCD (not including those super duper pointlessly expensive ones).

 

[Moloch]

that's a bit uncalled for don't you think?

Oddly enough this is one of the scenes that looks significantly better on the 8xs AA mode to me. Every other mode by both manufacturers has problems.

I'll rate them from best to worst as I see it:

1)nvidia 8xS mode by far
Excellent looking. Fine lines, very very subtle "missing parts" look I mentioned before. Best looking mode both up close and from a 3 foot distance.

2) ati 6x mode
Looks almost as good as the 8xS mode when viewed from atleast 3 feet from the monitor, but when view from 1-2 feet, it starts having that effect I tried to describe in my first post. It's like sections of the line are too thin.

3) slight edge to ATI's 4x mode

When viewed from 3 feet, ATIs mode looks better, almost as good as their 6x mode, though some slight "too thin" syndrom is apparent. When viewed up close, the "too thin" syndrom is noticable again and is slightly more pronouned.

4) nVidia 4x mode

When viewed from far away, does not look as nice as ATI's mode. staircasing is more apparent. When viewed from up close, does not suffer from the "too thin" syndrom that ATI's mode has, but at the same time makes the lines look slightly too thick and dark compared to their own 8xs mode and ATI's modes.

5) ATI's 2x mode slight edge

Has problems both up close and from far away with looking too "thin" in places. Some stairstepping is apparent.

6) nvidia 2x mode

Looks like nvidia's 4x mode with even worse stairstepping and still makes the lines too dark/thick.

Nite_Hawk

You're comparing super sampling to MSAA... I'd hope the performance cost of 8xs would look better.
I was purely looking at plain old regular MSAA.
I also don't know who you could think anything about what I said was uncalled for after reading this post and knowing I'm talking about purely MSAA.

Hi Nite_Hawk- and a rather interesting opinion. I can kinda see where you're coming from though.

A 300% zoomed & original of the wires points out what I believe you are saying. The ATI power lines have those grey blocks in-line with the cable (gamma correction, obviously) so the continuity of the cable here is "jagged" by a grey->black pattern rather than it being solid black:


I think your flatpanel is the missing link here. If I look at this on my trusty 19" CRT, the original size on the ATI looks much, much better due to the contrast with the lighter sky.. but on our Sony Flat Panel (with high contrast ratio), the lighter color makes the cables look almost "chainlink" from the gamma bits colorizing the cable line.

Interesting observation.. but I can clearly say the ATI 4x looks superior on my CRT.. the result of the gamma correction on the samples creates less of an "eyesore"... but the reverse is true on a high contrast ratio LCD- the black, grey, black, grey, black, grey pattern stands out ONLY on the LCD. Strangeness indeed and very, very interesting!

Indeed.. I have a trusy old hp 19" 1600x1200 .26 dot pitch *not so good* and I can easily see the difference between ati 4x and nvidia 4x.
Oh and TFT's pale in comparison to crts with contrast- the difference light intensity between the brightest white and the darkest black, not just the brightness of the picture although obivously that has a role in it.
Because of that fact (as of now) I won't be drooling over any lcds in the near future.

 

[Sharkfood]

Huh? Most CRTs have superior contrast ratio to LCDs.

The reversed was never stipulated, only that the effect seems to be limited to higher contrast ratio flat panel displays.

It could simply be any faultering or imperfections in TFT technology only "stands out" most naked-eye visibly on higher contrast models, which would be my guess. We have a generic LCD 400:1, Sony LCD is 800:1 Widescreen, and a Samsung 19" CRT. The grey-black-grey-black nature of the horribly JPEG aliased screenshots only rears it's ugly head viewing those screenshots on the Sony. So therefore a quick run upstairs to my roomey's Sony LCD was the only way I could empathize with Nite_Hawk's findings. I'm betting his Dell is also very high contrast...

My theory could be wrong.. perhaps, as Ailuros mentions, it could be dot-pitch, aspect ratio, HD/Widescreen related or otherwise. For now, I can agree that the gamma-corrected screenshots posted by HardOCP look superior for ATI on two out of three monitors here... but inferior (and quite detracting almost like a checkerboard) on one.

I should also mention I have similar beefs on my roomey's new LCD flat panel that most games look like doodie on it... it's like the first time you've plugged a Playstation2 to a monitor... you can see all sorts of artifacts apparent otherwise, but now very visible. Playing BF2 on his TFT looks ugly as every alpha-texture edge is very, very crisp.

Edit- and I agree with Radeonic.. I have a 19" Samsung CRT myself as I really do not care for what I've seen on the other two TFT's in the house.

 

[Moloch]

The reversed was never stipulated, only that the effect seems to be limited to higher contrast ratio flat panel displays.

It could simply be any faultering or imperfections in TFT technology only "stands out" most naked-eye visibly on higher contrast models, which would be my guess. We have a generic LCD 400:1, Sony LCD is 800:1 Widescreen, and a Samsung 19" CRT. The grey-black-grey-black nature of the horribly JPEG aliased screenshots only rears it's ugly head viewing those screenshots on the Sony. So therefore a quick run upstairs to my roomey's Sony LCD was the only way I could empathize with Nite_Hawk's findings. I'm betting his Dell is also very high contrast...

My theory could be wrong.. perhaps, as Ailuros mentions, it could be dot-pitch, aspect ratio, HD/Widescreen related or otherwise. For now, I can agree that the gamma-corrected screenshots posted by HardOCP look superior for ATI on two out of three monitors here... but inferior (and quite detracting almost like a checkerboard) on one.

I should also mention I have similar beefs on my roomey's new LCD flat panel that most games look like doodie on it... it's like the first time you've plugged a Playstation2 to a monitor... you can see all sorts of artifacts apparent otherwise, but now very visible. Playing BF2 on his TFT looks ugly as every alpha-texture edge is very, very crisp.

Edit- and I agree with Radeonic.. I have a 19" Samsung CRT myself as I really do not care for what I've seen on the other two TFT's in the house.

hehehe
What's disturbing to me is some people like my brother in law claim not to notice a difference in blackness between tfts and crts, ill have to point it out to him next time i'm over, as he still has a crt at home.

 

[Junkstyle]

The fact that you guys are having to enlarge the images by 200-300% and talk about individual pixels says something about the IQ differences. That being said on another note I really think ATI's Aniso is da bomb.

 

[Sharkfood]

The fact that you guys are having to enlarge the images by 200-300% and talk about individual pixels says something about the IQ differences.

You missed the point- the point being that enlarging by 200-300% illustrates what is visible on the TFT display at normal size for those of us where the normal size has the opposite effect. The alternating grey-black stands out on the TFT in those screenshots.. but looks yummy smooth on the CRT (and "cheapie" LCD) at normal size.

It does bring about an interesting thing- that a reviewer's qualitative IQ commentary about one particular method of IQ enhancement may have a reversed proportional effect on a different kind of display... but I can't make that statement until I've seen the actual hardware (and not jpg/compressed screenshots) in motion and "live"..

 

[L233]

Huh? Most CRTs have superior contrast ratio to LCDs.

This used to be true. AFAIK good CRT monitors have contrast ratios of 500:1, most have less. My 19" LCD is listed with a 1000:1 contrast ratio. Most recent VA-panel 19" LCDs have contrast ratios of at least 800:1. All modern LCDs have contrast ratios of at least 450:1. Even if the manufacturers' claims are full of shit (they usually are) I think it is safe to say that CRTs don't have an advantage over modern LCDs anymore when it comes to contrast.

And yes, ATI's AA on those wire screen shots looks like shit on my high constrast, high brightness LCD. It's unacceptable.

So it's either Nvidia's flickering AF or ATI's dotted-line AA. Great. That's like being given the choice between typhoid and cholera.

 

[Jawed]

LCDs, in my brief experience, have a default sharpening that is turned up way too high.

If the panel has a sharpening control, turn it to -1 or -2.

For some reason the panel manufacturers seem to think that maximising one's ability to perceive the edges of pixels is a good thing.

It's a horrible effect, quite unlike any normal representation of a picture in any other medium.

Jawed

 

[L233]

LCDs, in my brief experience, have a default sharpening that is turned up way too high.

If the panel has a sharpening control, turn it to -1 or -2.

AFAIK the sharpening control only works when you use the analog interface or when pictures are scaled. At least on my TFT it doesn't do anything when you use DVI.

 

[_xxx_]

The fact that you guys are having to enlarge the images by 200-300% and talk about individual pixels says something about the IQ differences. That being said on another note I really think ATI's Aniso is da bomb.

I see the quality of "regular" AA on absolutely the same level. There are always some areas of the picture where either side does better, but summed up it's a tie, definitely.

TrAA/AdAA is another story, nV is DEFINITELY better there. But this might as well be something that could change with new drivers. I believe the ATI's transparency AA is a pure SW solution and not implemented in HW, don't know for sure though.

Aniso is better on ATI, but not _that_ much better.

As you said, we reached the point where we must magnify the images to see any real difference, so both are very good

 

[Jawed]

AFAIK the sharpening control only works when you use the analog interface or when pictures are scaled. At least on my TFT it doesn't do anything when you use DVI.

The LCD I was testing with was using DVI.

Jawed

 

[L233]

The LCD I was testing with was using DVI.

Jawed

Many TFTs (and CRTs) ship with rather shitty factory presets but that is certainly not the reason why ATI's AA looks shitty on good TFTs in some cases.

 

[vember]

Then maybe it's because the gamma on many TFTs is all messed up?

Gamma corrected AA is 'as nature intended'. If it looks worse then that indicates that there might something wrong elsewhere in the chain.

 

[L233]

Then maybe it's because the gamma on many TFTs is all messed up?

Gamma corrected AA is 'as nature intended'. If it looks worse then that indicates that there might something wrong elsewhere in the chain.

No, the higher contrast and brightness of TFTs simply makes the shortfalls of ATI's AA algorithm apparent.

I've had a look at the screen shots on my old Iiyama CRT which has a feature that can boost the luminance to 190 candela, which is rather close to LCD levels. Guess what, the dotted-line effect is clearly visible there, too.

Looks like "gamma corrected" AA solves one problem just to introduce a new one. Frankly, I prefer the jaggies to the dotted line.

 

[vember]

I've had a look at the screen shots on my old Iiyama CRT which has a feature that can boost the luminance to 190 candela, which is rather close to LCD levels. Guess what, the dotted-line effect is clearly visible there, too.

I'm pretty damn certain that feature has a significant impact on the gamma response of the monitor.

 

[Jawed]

When you boosted the CRT's luminance, did you check that the gamma was correctly calibrated?

To ensure that the gamma is correctly calibrated, check the gamma 2.2 patch here:

http://www.aim-dtp.net/aim/evaluation/gamma_space/index.htm

LCD users reporting that the ATI AA looks wrong should check that their monitor is displaying the 2.2 patch correctly - that means there should be no colour visible in the greyscales - they should be entirely neutral.

If the greyscales show colours, click on other gamma values to see if you can find a greyscale that shows as neutral. When you do, report the gamma...

Jawed

 

[L233]

On my TFT it looks neutral at 2.0 or 2.1 (hard to tell). At 2.2 there is a very slight, very hard to spot coloration. I've tweaked gamma a bit and it makes absolutely no difference wrt to the wire screen shot.

 

[Kombatant]

TrAA/AdAA is another story, nV is DEFINITELY better there. But this might as well be something that could change with new drivers. I believe the ATI's transparency AA is a pure SW solution and not implemented in HW, don't know for sure though.

It's definitely the drivers, and it will get better. As for nV's TxAA, I didn't know they had dedicated hardware that does it...? Can someone throw me a link where that is explained, I always thought it was just a driver feature.