Author Topic: Too much contrast on MacBook ?!  (Read 10928 times)

EVZML

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Too much contrast on MacBook ?!
« on: July 21, 2014, 05:44:56 PM »
Hello.
So I received my 50D some days ago and I'm very happy - dope quality!
But..I have a contrast problem with my converted .mov (h.264) files.
I'm editing on a PC using Davinci Resolve Lite, exported to .mov it looks good in VLC and Win MediaPlayer. BUT: when I open the files on my MacBook, the files have sooo much more contrast.

Here is my workflow:
-Recorded on my 50D (RAW, not MLV), using a Komputerbay 64GB 1050x
-use raw2cdng (1.5.0. beta6) settings: CDNG16bit, no other options clicked.
-import files into Davinci Resolve 11 Lite, in Camera Raw changed to:
Decode using: Clip
Color Space: BMD Film
Gamma: BMD Film
-Render Settings: QuickTime, Codec: H.264

Opened the files on some devices:
-Windows PC (where I edit): looks very good!
-Windows Notebook: looks still good!
-MacBook: looks bad, soo much more contrast! (QuickTime Player, VLC - same problem)
-iPad: More contrast then on my WinPC, but less then on MacBook. Looks OK, but still very different compared to PC!

So...somebody can tell me what I do wrong? I edit videos since some years, I know the MacBook display is a little bit different, but not that much different. Maybe it's something with the Codec?

Thanks for any help!!
-EVZML


barepixels

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Re: Too much contrast on MacBook ?!
« Reply #2 on: July 22, 2014, 01:16:12 AM »
also. might want to view on another mac laptop
5D2 + nightly ML

EVZML

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Re: Too much contrast on MacBook ?!
« Reply #3 on: July 23, 2014, 07:29:33 PM »
Thanks Audionut and barepixels for your help! But I did some tests and now I think it's a codec problem.
When I export my project as H.264, it all looks good on my PC. But when I export to MPEG4, it get the same contrast problem on my PC!
So I tried playing those files on my different systems and found out the following:

PC:
-.H264: looks perfect
-MPEG4: too much contrast

iPad:
-.H264: looks good (the ipads display has just a little bit more contrast)
-MPEG4: too much contrast

MacBook:
-H.264: too much contrast
-MPEG4: too much contrast


The H.264 and the MPEG4 file looks exactly the same on my MacBook!
So 2 questions:
Why does the files looks different on my other systems, but looks the same on my MacBook??
And Why does MPEG4 and H.264 output looks sooo much different??? I mean it's not just a little bit more contrast, it's the whole video has sooo much more contrast and it has to much saturation. And also I loose all the details because it's too dark!!

Somebody ever had the same problem, or know more about problems like that???

Thanks to everybody who try to help me!  :)


EDIT: H.264 and MPEG4 does NOT look the same on my MacBook. But it does not have the same big difference than on my PC.
I mean when I play back a raw video file that was not edited, it should not have much contrast, right?!
HEEEEEEELP  >:(  :'(

PressureFM

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Re: Too much contrast on MacBook ?!
« Reply #4 on: July 23, 2014, 08:06:08 PM »
Check your screens gamma value. Should be 2.2.

dyfid

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Re: Too much contrast on MacBook ?!
« Reply #5 on: July 25, 2014, 08:54:07 AM »
Multitude of possible reasons for this and the issues between mac and PC playback is so common. Split into three areas. Display chain, media player handling and encoding.

Like differences in levels handling and colour space caused by different physical interfaces DVI & hdmi hardware acceleration on or off, calibrated display chain or winging it, media player quirks, wrong encoded video levels.

A good place to start is calibrate your screens and nail the display chain, make sure Resolve is properly set up, that you encode to restricted range, so you know output is correct from Resolve then go through the same calibration process with a media player that works properly, that can be colour managed and slowly work through the problems eliminating the problems as you go.

jimmyD30

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Re: Too much contrast on MacBook ?!
« Reply #6 on: July 25, 2014, 01:16:00 PM »
 I think a lot of us are dealing with this issue to some degree. If really going for professional work product, then calibrated external monitor with external vectorscope is necessary, but expensive.

Some additional things you can do without that stuff is to include watching on HDTV via HDMI (especially if TV is your final medium), but even different HDTVs will give you different looks. Also try setting color values using waveforms, histograms, and vectorscope with your computer monitor according to where your video will be viewed, web, tv, theater, etc., as each uses a different color space.

dyfid

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Re: Too much contrast on MacBook ?!
« Reply #7 on: July 25, 2014, 02:34:14 PM »
I think a lot of us are dealing with this issue to some degree. If really going for professional work product, then calibrated external monitor with external vectorscope is necessary, but expensive.

The cost to calibrate a monitor or even HDTV is not that much, compared to the expense of software, camera upgrades and all.

It's more about time, to read, learn and put calibration into practice. £160 for an Xrite i1DisplayPro probe and if possible a £95 Blackmagic Mini Monitor Interface either Thunderbolt for Mac or PCI for PC. Download HCFR & DispcalGUI both free and very capable, DispcalGUI will also build a high precision monitor LUT for Resolve, without it even Resolve is not colour managed.

The calibration, profiling and view LUT building will clear up many of the OP's issues above, apart from various codec handling differences with QT between Windows and Mac, but at least we learn what is working right and what is just wrong and avoid it or fix it.

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Some additional things you can do without that stuff is to include watching on HDTV via HDMI (especially if TV is your final medium), but even different HDTVs will give you different looks. Also try setting color values using waveforms, histograms, and vectorscope with your computer monitor according to where your video will be viewed, web, tv, theater, etc., as each uses a different color space.

Why not just calibrate the display whether TV or monitor to as close 709 as it's capable of and a gamma that suits the room viewing conditions, 80cd/m2 for dim lighting, 100cd/m2 for brighter. 709 has no specified gamma unlike sRGB.? Scopes for analysis and colour correction, grading is about aesthetics by eye.

Video standard for HD is 709 whether web browser, media streamer, theater wherever, SD resolutions are more dependent on location in the world but even then still 709 primaries generally. Only time alternative to 709 for HD and higher resolutions for the time being, would be P3 for cinema but then really only when grading by projector.

Levas

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Re: Too much contrast on MacBook ?!
« Reply #8 on: July 25, 2014, 03:33:52 PM »
Isn't this issue caused by quicktime and the quicktime H.264 codec.
Quicktime always shows video's brighter then they are, uses higher gamma I believe.

Try this, import a jpg in quicktime, and now open the same jpg in finder.
The shadows in quicktime are brighter...

dyfid

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Re: Too much contrast on MacBook ?!
« Reply #9 on: July 25, 2014, 11:48:41 PM »
Isn't this issue caused by quicktime and the quicktime H.264 codec.
Quicktime always shows video's brighter then they are, uses higher gamma I believe.

Partly true, QT h264 on the mac is encoded incorrectly. On Windows QT h264 is encoded correctly. But again it's important the display chain is proven correct by even basic calibration. There are a number of links in the display chain where levels and gamma can be mishandled, even giving results that look right after been mishandled but only because the rest of the chain is also mishandling it and pushing it back, but excessive banding can give that away.

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Try this, import a jpg in quicktime, and now open the same jpg in finder.
The shadows in quicktime are brighter...

On Mavericks? That sucks, with QT becoming defunct and AV Foundation taking over, which is what FCPX is based on now I believe, QT only being used for codecs not supported by AV Foundation and being re-encoded to be compatible, which appears to be what's happening, wonder how good AVF will be.

reddeercity

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Re: Too much contrast on MacBook ?!
« Reply #10 on: July 26, 2014, 02:21:00 AM »
If you are getting gamma shift and you have used your scopes to keep it in the Rec.709 Color space (16-235)
The most likely problem is color correction on a un-calibrated monitor usually in full color (0-255) and gamma of 1.8 (default on Mac)
Now if you have adjusted your display with a colorimeter or at least with the Mac Monitor calibrated software   
Then turn off Automatic gamma adjustment in the ProRes Codec option , I assume your intermediate mov is ProRes .
I use Apple compressor for all my H264 and never had a gamma problem between PC & Mac , it's the same h264 I upload to Vimeo & YouTube.


dyfid

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Re: Too much contrast on MacBook ?!
« Reply #11 on: July 26, 2014, 10:20:05 AM »
If you are getting gamma shift and you have used your scopes to keep it in the Rec.709 Color space (16-235) The most likely problem is color correction on a un-calibrated monitor usually in full color (0-255) and gamma of 1.8 (default on Mac)

Whether using restricted or full range for monitoring / scopes doesn't matter as long as the display chain in Resolve is expecting full or restricted, could be limited RGB over DVI/SDI/hdmi or 4:2:2 or 4:4:4 as long as the display can handle and capable of excepting that signal. Quite acceptable and preferred by many to monitor full range, as long as when encoding for final output limited range encoding is chosen in Resolve's delivery tab. Or full range if going to an intermediate. So full range RGB on a mac is no problem if that's the default for an Apple display.

Gamma is 2.2 default for me on Mavericks not 1.8 and I've not been in messing with those settings it's worthless.
 
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Now if you have adjusted your display with a colorimeter or at least with the Mac Monitor calibrated software

1. Get the display into a acceptable state (as close to 709 standard as possible) for profiling and 3D view LUT creation by using the displays hardware controls, if the display doesn't have decent controls it could well be limited for calibration if it's drifting, just useful for GUI.

2. Ensure no ICC profiles are interfering with the display's gamma. Difficult to kill on a mac.

EVZML is using Resolve so:

3. Use a probe (i1DisplayPro) and suitable calibration software (hcfr to report, DispcalGUI to profile/LUT) to control the Patch Generator in Resolve, probe checks patches from within Resolve GUI or preferably patches on an external display fed by a Blackmagic Mini Monitor to bypass any levels scaling through the vidcard interfaces, DVI, hdmi, DP.

4. Build a 3D LUT for monitor based on rec709, D65 & BT1886 gamma with 2.4 power curve.

5. Put 3D LUT (.cube) in Resolves 3D Monitor LUT slot and set Viewer LUT to Monitor LUT.

Now have calibrated monitor and colour managed app. Resolve doesn't use ICC profiles so all that is redundant including OSX's calibration by eye guff.
   
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Then turn off Automatic gamma adjustment in the ProRes Codec option , I assume your intermediate mov is ProRes .
I use Apple compressor for all my H264 and never had a gamma problem between PC & Mac , it's the same h264 I upload to Vimeo & YouTube.

Resolve's QT h264 output on the mac is incorrect, Windows isn't. But one thing I agree with you is that going to an intermediate codec and then encoding h264 etc from that is better route. Me I use x264 and apps like Handbrake for that.

Web, Vimeo & Youtube output through a browser on a PC or mac I wouldn't judge anything on personally.

EVZML

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Re: Too much contrast on MacBook ?!
« Reply #12 on: August 13, 2014, 10:55:27 AM »
First of all, thanks to everybody that is helping me here!

@jimmyD30: Most of my productions will only be for YouTube & Vimeo, but right now I'm also producin something for German TV. But I recorded that stuff without Magic Lantern, and had no problemes with it. But for the future, I wanna get my RAW-Videos into the same (or better into a higher level). RAW-Videos are really nice if it comes to shaprness, but the contrast difference right now is a big problem. Expensive monitor stuff is not in my price range right now.

@Levas: I also have the VLC media player on all my computer systems. Does not make a huge difference.

@dyfid: "QT h264 on the mac is encoded incorrectly. On Windows QT h264 is encoded correctly."
Really? WOW! Maybe this is the problem. Would it look correctly on Mac if I would upload the video on youtube/vimeo?

@reddeercity: I don't even have ProRes output in Davinci Resolve (Win)! QuickTime player is installed.

@dyfid: I don't really understand all of that. I will do some google search in the next days to understand what you mean :)


dyfid

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Re: Too much contrast on MacBook ?!
« Reply #13 on: August 14, 2014, 12:17:34 AM »

@dyfid: "QT h264 on the mac is encoded incorrectly. On Windows QT h264 is encoded correctly."
Really? WOW! Maybe this is the problem. Would it look correctly on Mac if I would upload the video on youtube/vimeo?


I'm on a hackintosh, use Resolve on mac and windows and checking the output from h264 from mac Resolve 11 & Win Resolve 11. Mac is always restricted range regardless of choice in Resolve of data or video levels for encoding but more importantly doesn't matter what combination of settings mac h264 doesn't convert back to same levels and gamma as the input like Win h264 does.

Can only assume mac h264 even from Resolve is meant for decompressing via QT on a mac's rather than respecting a standard for all platforms regardless of OS.

But really best advice is to encode to an decent intermediate format, on windows that would be DNxHD I'd suggest and then encode that through something like Handbrake using x264. A proper h264 encoder. :) Only problem is DNxHD is restrictive regarding frame rates and resolution. So for some of the more exotic aspect ratios of ML raw you'll end up encoding with letterbox to DNxHD to get the typical 1920x1080 frame size. No problem though, if you want to do your final encode and upload non letterboxed, say 1920x816 it's easy to add a crop operation in handbrake or similar when encoding to h264.

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@dyfid: I don't really understand all of that. I will do some google search in the next days to understand what you mean :)

Nor me, funny that. :)