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HELP! Dark scenes TOO Dark. Light scenes great!

post #1 of 19
7/24/09 at 6:25am
Thread Starter 
Setup.

Nvidia 8700M.
DVI -> HDMI straight to Projector.
1920x1080p @ 60.
Nvidia set to 0-255.


Light scenes are AMAZING and PERFECT.
Dark scenes are TOO DARK and lose detail.

What is going on?
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post #2 of 19
7/24/09 at 7:38am
If you adjust your brightness, can you see all the black boxes?

http://www.shonk.org/Brightness.jpg
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post #3 of 19
7/24/09 at 7:43am
Quote:
Originally Posted by mkedda View Post

Setup.

Nvidia 8700M.
DVI -> HDMI straight to Projector.
1920x1080p @ 60.
Nvidia set to 0-255.


Light scenes are AMAZING and PERFECT.
Dark scenes are TOO DARK and lose detail.

What is going on?

I'm not 100% on how this works, but this should give you an idea or the problem...

This is a fundamental problem with 0-255 vs 16-235. You can either choose to crush blacks, or get a washed out looking bright picture.

It all comes down to how your video card interprets your video and how the device drivers are designed. Worst case scenario you're fighting both, which I believe is a problem with Nvidia cards. When set to 16-235 it's actually applying it in the card as well as on the video, so you get something like
32-225. If you go with 0-225 and actually get it, the 16-235 source material ends up getting crushed.

I ended up going with light brights

I think you can find some of the answers in the color correction thread
More discussion at Nvidia regarding black crush

Mike
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post #4 of 19
7/24/09 at 7:53am
Mike, that's not accurate... I have full blacker than black and whiter than white and no washed out colors... I use an ATI Videocard, CoreAVC and have my TV ISF Calibrated.
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post #5 of 19
7/24/09 at 8:21am
Quote:
Originally Posted by craysv1 View Post

Mike, that's not accurate... I have full blacker than black and whiter than white and no washed out colors... I use an ATI Videocard, CoreAVC and have my TV ISF Calibrated.

Can you explain how you managed this feat?

Mike
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post #6 of 19
7/24/09 at 8:32am
Samsung 67A750 ISF Calibrated to the HD color gamut set to 0-255. Core AVC handling all my x264 duties (99% of my usage) set to 0-255 (although I have confirmed BtB, WtW on Xbox360, PowerDVD (Bluray) and DirectTV (HDNET Calibration)).

Connection via DVI-D to HDMI adapter from my HIS H467P1GP Radeon HD 4670.
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post #7 of 19
7/24/09 at 10:39am
Quote:
Originally Posted by craysv1 View Post

Samsung 67A750 ISF Calibrated to the HD color gamut set to 0-255. Core AVC handling all my x264 duties (99% of my usage) set to 0-255 (although I have confirmed BtB, WtW on Xbox360, PowerDVD (Bluray) and DirectTV (HDNET Calibration)).

Connection via DVI-D to HDMI adapter from my HIS H467P1GP Radeon HD 4670.

What do you do for MPEG-2, like OTA signals recorded using Media Center?

Mike
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post #8 of 19
7/24/09 at 11:20am
I don't... DirecTV for TV Viewing... I do download some x264 encoded TV Shows occasionally which obviously work fine with CoreAVC. Anything else is set to play with MPC Home Cinema with PowerDVD's MPEG2 codec (which works well with BtB/WtW on MPEG2 dvd ISO's) and whatever other codecs for other formats that come with the CCC Codec Pack
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post #9 of 19
7/24/09 at 12:50pm
Quote:
Originally Posted by craysv1 View Post

I don't... DirecTV for TV Viewing... I do download some x264 encoded TV Shows occasionally which obviously work fine with CoreAVC. Anything else is set to play with MPC Home Cinema with PowerDVD's MPEG2 codec (which works well with BtB/WtW on MPEG2 dvd ISO's) and whatever other codecs for other formats that come with the CCC Codec Pack

Based on your response, it looks like you found a solution for your situation. However, it's an issue for other HTPC user and is still a persistent problem.

I'm still curious as to what you considered not "accurate" in my post. As I stated, I'm not 100% sure about what exactly comes into play in the black crush even when crush problem, but a problem does exist. Just because a work around exists doesn't mean the problem doesn't exist.

I'm more than happy to learn if you can share more about the nature of the problem. The CoreAVC suggestion was helpful. However, just stating that something is not accurate without any sort of explanation doesn't really help.

Regards,

Mike
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post #10 of 19
7/24/09 at 2:48pm
It also has to do with owning a Samsung LED DLP. Those TVs beat the crap out of most sets in color accuracy
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post #11 of 19
7/24/09 at 2:55pm
Well, I'm not home... I'll post all my specs, settings, etc over the weekend.

However, the TV has been ISF Calibrated... I have also verified with my iOne calibrator that all my colors, contrast, brightness and gamma are as close to perfect as possible on my HDTV when playing Bluray and x264.

I also verified, in the past, that not only CoreAVC was accurate but Mediaportal's internal x264 codec.

I'm assuming that most people who have issues are due to incorrect, conflicting or unchangeable settings between their TV and HTPC. I switched over from an nVidia card to an ATI about 8months ago and the nVidia was also calibrated properly.
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post #12 of 19
7/24/09 at 3:04pm
Quote:
Originally Posted by mkedda View Post

Setup.

Nvidia 8700M.
DVI -> HDMI straight to Projector.
1920x1080p @ 60.
Nvidia set to 0-255.


Light scenes are AMAZING and PERFECT.
Dark scenes are TOO DARK and lose detail.

What is going on?

Sounds like your TV is expecting video levels (0-235) and you're feeding it PC levels (0-255).

Option 1) Change your "Dynamic Range" setting to "Limited (16-235)". This will fix video but leave everything else crushed.

Option 2) Check your TV, see if it has an option along the lines of "PC" vs "Video" or "0 IRE" vs "7.5 IRE", or "Expanded RGB" or something like that. With the above settings you want it set to PC or 0 IRE or something like that.

Option 3) If that doesn't work or you don't have it. Try adjusting the brightness control up and see if that uncrushes black.
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post #13 of 19
7/24/09 at 3:35pm
Quote:
Originally Posted by craysv1 View Post

Well, I'm not home... I'll post all my specs, settings, etc over the weekend.

However, the TV has been ISF Calibrated... I have also verified with my iOne calibrator that all my colors, contrast, brightness and gamma are as close to perfect as possible on my HDTV when playing Bluray and x264.

I also verified, in the past, that not only CoreAVC was accurate but Mediaportal's internal x264 codec.

I'm assuming that most people who have issues are due to incorrect, conflicting or unchangeable settings between their TV and HTPC. I switched over from an nVidia card to an ATI about 8months ago and the nVidia was also calibrated properly.

I'm not challenging that your system is properly calibrated for your CoreAVC/x264 setup. However, I think it's important to point out a few things.

Color performance is influenced by a couple of things.

1: The sets capability.
2: The sets configuration, there are settings that can cause picture issue, set dependent.
3: The source material itself can cause issues. Depending on how it was encoded. 16-235 vs 0-255 this will affect how the final video looks like on your system. Things like CoreAVC can address that problem, but what about formats other than x264. My main need would be for Mpeg-2 HD OTA streams.
4: Hardware/Drivers: Some gfx cards have limitations to one or both factors...

I think the main thing to note is, you my be able to calibrate for a particular setup/source, but you may experience a bad picture depending on what you feed the PC. It's not that the set or system is not properly setup. It could just be an issue with the source material. As craysv1 has done, he's optimized for his majority use.

Mike
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post #14 of 19
7/24/09 at 3:47pm
HDMI is a nightmare.

With VGA or DVI it is easy. Set your player's (Zoomplayer or MPC-HC) Renderer to leave the levels alone (black at 16, white at 253, therefore passing Blacker-than-black and Whiter-than-white).

Adjust your brightness. Adjust your gamma.

Done.


(PanamaMike, all proper video is 16-235. The only 0-255 video I know of is captured video games.)
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post #15 of 19
7/25/09 at 6:02am
Quote:
Originally Posted by PanamaMike View Post

I'm not challenging that your system is properly calibrated for your CoreAVC/x264 setup. However, I think it's important to point out a few things.

Color performance is influenced by a couple of things.

1: The sets capability.
2: The sets configuration, there are settings that can cause picture issue, set dependent.
3: The source material itself can cause issues. Depending on how it was encoded. 16-235 vs 0-255 this will affect how the final video looks like on your system. Things like CoreAVC can address that problem, but what about formats other than x264. My main need would be for Mpeg-2 HD OTA streams.
4: Hardware/Drivers: Some gfx cards have limitations to one or both factors...

I think the main thing to note is, you my be able to calibrate for a particular setup/source, but you may experience a bad picture depending on what you feed the PC. It's not that the set or system is not properly setup. It could just be an issue with the source material. As craysv1 has done, he's optimized for his majority use.

Mike

Actually, I did make sure all major formats worked... DVD is MPEG2 and it works great and is properly calibrated.

I'll try to get all my settings up later... Stanger managed to cover all the basics, however.
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post #16 of 19
7/28/09 at 9:39am
Thread Starter 
I have the following options to choose for Computer Input.

Which should I chose?

AUTO
The proper setting is automatically selected.
RGB
Select this option when connecting the projector to high defi nition
video equipment having R, G, and B output terminals.
YCBCR / YPBPR
Select this option when connecting the projector to a DVD player or other
device having Y, CB, and CR (or Y, PB, and PR) component video output
terminals

Quote:
Originally Posted by stanger89 View Post

Sounds like your TV is expecting video levels (0-235) and you're feeding it PC levels (0-255).

Option 1) Change your "Dynamic Range" setting to "Limited (16-235)". This will fix video but leave everything else crushed.

Option 2) Check your TV, see if it has an option along the lines of "PC" vs "Video" or "0 IRE" vs "7.5 IRE", or "Expanded RGB" or something like that. With the above settings you want it set to PC or 0 IRE or something like that.

Option 3) If that doesn't work or you don't have it. Try adjusting the brightness control up and see if that uncrushes black.
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post #17 of 19
7/28/09 at 9:48am
None of those appear to relate to video levels.
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post #18 of 19
11/16/10 at 8:14pm
Quote:
Originally Posted by stanger89 View Post

Option 1) Change your "Dynamic Range" setting to "Limited (16-235)". This will fix video but leave everything else crushed.

I know its an old thread, but this solved my problem. My computer didn't automatically detect that it needed to set it to limited, and I had to manually set it. It might be because of the DVI -> HDMI connector, making the computer think its hooked up with a monitor. With this set to 0-255 (default) only VLC with "Use Hardware YUV -> RGB" checked on an nvidia 8800gt displayed properly. All other players (xmbc, mpc) and computers with radeon cards, or VLC with that option unchecked were too dark and lost all detail.

Hope this helps someone in the future.
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post #19 of 19
11/16/10 at 8:58pm
Quote:
Originally Posted by jrwalte View Post

It also has to do with owning a Samsung LED DLP. Those TVs beat the crap out of most sets in color accuracy

Amen to that!
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