Monitor Calibration, ProRes, and QT prefs

I have been having a lot of problems with color reliability playing ProRes files in QT.

I use a double monitor set-up for editing and calibrate the monitors with a Datacolor Spyder 3 Elite...
23" Apple Cinema HD
24" Dell 2408WFP

I'm shooting video on a Canon 7d, compressing to ProRes in Compressor. When I play the ProRes files in QT (not in FCP) they look over-saturated and contrasty. If I turn OFF "Enable Final Cut Studio color compatibility" in QT preferences the ProRes files look fine. This doesn't seem right but it's the only way I can get reliable color playback of ProRes files in QT.

However, If I take these same files and play them on my 15" MacBook Pro (which I've just noticed has QT 7.6.4) all the files look fine. The FCS color compatibility preference is ON.

Obviously, I am going to keep the preference turned off on my desktop but...it seems really strange.

OS 10.5.8
ATI Radeon HD 2600
FCP 6.0.6
QT 7.6.6
Compressor 3.0.5

Why are you judging color on a computer monitor? Computer monitors might as well be black-and-white, for all the good they do displaying broadcast color.

Because most of my work is for online viewing.
And, I calibrate my monitors.
I have very accurate color.

I have a A Sony CRT broadcast monitor when I need broadcast calibrating.

The Problem I am describing has to do with playing ProRes files in QT...I don't believe it has anything to do with my monitors.

This is a recent problem so I didn't know if it was the calibration software, the custom color profiles, Compressor settings, or if something was up with QT. I'm pretty sure it's the QT preference but I wanted to see if anyone else has run into this problem.

Is your computer set up to display at a gamma of 1.8?



www.strypesinpost.com

I'll note that OS 10.5.x defaults to gamma 1.8 whereas OS 10.6.x defaults to 2.2. Quicktime X (OS 10.6.x) doesn't have the FCP compatibility option. Basically gamma has changed between the two OSs. That might add to the confusion.

You mention calibrating the monitor but to what are you calibrating it to? It probably should be to 2.2 (which is what Windows uses as well) but then you will see a difference in OS 10.5.x

I suspect you're not "delivering" in ProRes. If memory serves me, MPEG4 (H.264) has built in abilities to gamma adjust depending on whether being served to Mac or Windows.
[www.kenstone.net]

Quote
With MPEG 4 the gamma correction process is not necessary as the MPEG 4 codec automatically buries 'Color Sync' profiles in the QT movies. At playback, the MPEG 4 QT movie will check the platform of the viewer and adjust gamma automatically, serving up a gamma corrected version for that platform, Mac or PC. This is a powerful feature.

But who knows if that ever worked properly. Many people note a gamma shift when encoding to H.264 .mov as well (Apple's codec) which may not happen when encoding to other H.264 codecs (x264, MainConcept).

Its a big problem with QTX, QT7, FCP, H264 (including 5/7D footage) and especially converting to and from ProRes.

Read this article:

[motionlifemediablog.wordpress.com]

and get the beta of 5DtoRGB to test the workflow for yourself:

[rarevision.com]

Hopefully this will help minimise your colour inconsistencies.



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

Ben King Wrote:
-------------------------------------------------------
> Its a big problem with QTX, QT7, FCP, H264
> (including 5/7D footage) and especially converting
> to and from ProRes.
>
> Read this article:
>
> [motionlifemediablog.wordpress.com]
> 2/5dtorgb-color-tests/

A few comments about the blog entry (and other things)...

Most video specifications include a gamma setting, so it shouldn't be an option in most cases (like it is in the 5D to RGB conversion software).

There is no default system gamma in Mac OS X, per se. When OS X creates a color profile for a particular monitor in Snow Leopard (10.6.x), it defaults to a gamma of 2.2, if another value isn't specified. Previous OSes don't automatically create a color profile and will use a factory default profile if it finds one (or it will fall back to a "generic" profile). Color profiles in all versions of OS X can have any gamma setting.

Prior to version 7 of FCP and OS X 10.6, FCP assumed that your monitors were calibrated to a gamma of 1.8 (to get a close approximation of a broadcast display in the Viewer and Canvas windows --- see Alexis van Hurkman's FCP Apple Certified Training Series books for more info). I am not sure if FCP 7 under OS X 10.6 changes anything (about FCP's monitor profile gamma setting assumption --- I haven't seen any mention of a change in any of the FCP7 docs or release notes).

So, while OS X 10.6 uses a gamma of 2.2 for its automatically-generated monitor color profiles, FCP 7 still may assume that you are using a gamma of 1.8 (again, you should be using an external, properly set up broadcast monitor for evaluating your video). Also, monitor color profiles may affect what you see on your computer screens, but they don't change the contents of the media files (something which is lost to many of us).

What you see on your computer monitor(s) is directly affected by the monitor profile(s) in use (and the included gamma settings). So, screen shot images of various windows in various applications may not be accurate and therefore not a reliable means for comparing how different applications display video. Yes, it is a mess, and QuickTime X just adds another layer of confusion and complexity.

The only accurate way to view and track the look of video media is via a properly set up, external broadcast monitor (via a proper video I/O card, not via a computer's display ports). Video and computer displays typically use different color spaces (among other things).

The idea is to set up and use a proper referenced based system. For computer-delivered media, you have to pick a set of typical parameters that you expect most users to have in-place on their computers. You then set up your reference system to these specifications and target your deliverables to that system. Like TV sets, which are rarely properly set up and adjusted in people's homes, you don't have any control over how most people's PCs are set up. All you can do is use a "best case scenario" reference system for web/PC media delivery, or a broadcast spec'd reference system for broadcast TV delivery (or satellite, etc.).

---

All this aside, there are some quirky issues with gamma within FCP (e.g., create a "Text" generator at 50% gray and drop it into a non-RGB codec sequence and it will show up as 56% gray on the video scopes, whereas the same gray text created in the Boris Title 3D generator properly shows up in the sequence as 50% gray). There are also issues with how gamma and other color space metadata information is interpreted by various playback applications, or tools like Compressor, MPEG Streamclip, etc. And, whether or not this information gets included, properly or not, is a big problem in QuickTime itself, as well as other third-party tools.

Yeah, it's a mess... enough to drive one to do many different things...



-Dave

Thanks Ben and D-Mac.

I have my monitors' gamma calibrated to 2.2.
I only use my Apple Cinema HD for color correcting as I can't get the Dell to properly calibrate.
I can get it close but not spot on.

Most of my deliverables are as either H.264, flash, or even swf.
However, I work and export in ProRes and need to check these files prior to compression.

As per my first post, the real problems come from selecting the "Enable FCS color compatibility" box in QT 7.6.6 preferences and its effect on ProRes files. If the pref box is not selected the color and contrast shift go away. I am now leaving it unselected. Problem solved?

I'm avoiding Snow Leopard and the new QT for now so I can keep my work environment somewhat stable.

I will read the posts you suggest.

Thanks again,

Pons

Final Cut Pro automatically adjusts its computer display to show 2.2 if you swap the system to 1.8

So whatever gamma you are using you should see the FCP display as a reasonably close approximation to the 2.2 (there is a very slight shift in the very darks when switching).

Quote

As per my first post, the real problems come from selecting the "Enable FCS color compatibility" box in QT 7.6.6 preferences and its effect on ProRes files. If the pref box is not selected the color and contrast shift go away. I am now leaving it unselected. Problem solved?

The only problem is when grading for web using the FCP Canvas window...

...the view you see in the Canvas IS the view you get in QT7 WITH the "Enable Final Cut Pro color compatibility" ticked!

My suggestion is to grade your stuff and test a variety of output options and use the one you think looks best and as long as you and the client is happy thats all that matters - after all you are not subject to a Technical check as we do for Broadcast.



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

>I have my monitors' gamma calibrated to 2.2.

Apple's traditional gamma value is set to 1.8, which is good for viewing work in a bright desktop environment. 2.2 is usually used for video, and it is created with the assumption of a dark viewing environment. The FCP canvas is the last place to judge your color or picture quality because it was not built for it.

>the real problems come from selecting the "Enable FCS color compatibility"

The "Enable FCS color compatibility" option assumes that your display is calibrated at 1.8 gamma, and will make adjustments to correct the video so it looks normal in the FCS canvas and in Quicktime. I am not sure how far SL's gamma change affects ProApps, but from what I've seen, not much and you should still calibrate your display for 1.8 gamma, and let FCS/QT do the color adjustment.



www.strypesinpost.com

Sorry G but you don't need to calibrate your monitor to 1.8 Gamma anymore - as I mentioned above:

Quote

Final Cut Pro automatically adjusts its computer display to show 2.2 if you swap the system to 1.8

Create a 1.8 and a 2.2 Calibrated Profile in your Display Prefs and test it for yourself.

Also Pons is creating output for the desktop via the web and NOT broadcast and as such grading for this using an Apple Cinema Display which is fine.

The problem is not just a Gamma issue. Different exports create different issues and output (even with the same source) can vary considerably from app to app.

Even exporting a ProRes 422 HQ to a Self-contained QT movie from FCP looks different (even with Enable FCS color compatibility ticked) to an export Using Quicktime Conversion to ProRes 422 HQ!



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

A while ago I noticed that the image on the canvas looks slightly darker (and different) if your monitor is calibrated to a display of 2.2, whereas the image on the canvas looks closer to a CRT if you calibrated the monitor to 1.8. That was in FCS 6/Leopard. I never trusted a computer monitor for CC work, partly because I'm not sure how Apple does the Rec 709/601 to RGB conversion, and different conversion algorithms and profiles will have a different result. Not to mention that if you were trying to CC dimly lit footage, you get this purple hue that you don't see on a broadcast monitor.

>Even exporting a ProRes 422 HQ to a Self-contained QT movie from FCP looks different (even with Enable FCS color
>compatibility ticked) to an export Using Quicktime Conversion to ProRes 422 HQ!

QT Conversion is never recommended for final exports, because it is noisier, and 8 bits only. Also, if your footage is rendered, QT conversion tends to work off the rendered files. Whereas if your footage was rendered, and you are exporting a SCQT under current settings, FCP will pull frames from the rendered files.



www.strypesinpost.com