viewing accurate color, or at least gamma in FCP

[Glenn Chan]

To get accurate color, you’re looking at the following:

A- Calibrating the interface. With broadcast monitors, you do this via color bars. For computer monitors hooked up via DVI, it’s digital so the interface doesn’t go out of calibration.

B- Calibrating the monitor for grayscale tracking (i.e. are black and white images perfectly black and white). The lower-end broadcast monitors don’t let you do this. On the mid-high end ones, you can manually tweak the monitor controls to get close. Probes by Sony, Ikegami, and Minolta can automate the process and make it more objective.

For home theatre, there’s some device for doing this. Because the controls are rather crude, they can’t fix serious grayscale problems (i.e. from a CRT aging). For critical color, CRTs should eventually be replaced.

For print work, various monitor profiling devices like the iOne handle this. If you want to adapt this for video use, hopefully the iOne messes around with the video card’s LUT to load the calibration there. This will carry over into FCP.

You may also want to calibrate the monitor for gamma, white point, white level.

C- Some monitors like the aluminium apple cinema display have color problems which can’t be calibrated away. There may be some other monitor defects that you can’t calibrate off (i.e. LCD black level glow)

For video work (especially SD), not showing interlacing is something you can’t fix.

D- Differences in color gamut between the monitoring display and the output device.

In your situation, your computer monitor’s color gamut is likely different from the reference standard (SMPTE C, EBU, or Rec. 709). I don’t know of any cheap tools to fix this. For TV work, this is not a problem when you monitor with a reference-grade monitor (i.e. a CRT with SMPTE C phosphors).

For print work: The output device’s color will vary depending on ink and paper. To handle this, you can use color management systems like ICC. The iOne probably is designed to generate ICC profiles.

ICC was never designed to work with video. Real-time performance is not there. Also, you don’t need it for TV work (you just get a reference-grade monitor). For film output work (i.e. DI), there are 3D LUT solutions available (i.e. Truelight).

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The simple solution for SD work is to get a broadcast monitor / reference-grade monitor. The entry level ones are around $500 (not the greatest color, but better than other options at the same price). Use a DV camera to go from firewire to monitor.

For HD work, I think the cheapest CRTs are around $5k.

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To answer your question:
Hopefully the iOne can tweak your video card’s LUT to achieve the desired gamma.

I’m actually not sure what the correct gamma is…

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I don’t believe FCP has any color management per se. However, there are some behaviors to note:

A- When the timeline is not playing, I believe FCP will decode the Y’CbCr video signal to 0-255 RGB (RGB color, with black at 0 and white at 255). When the timeline is playing, it will decode to ~16-~235 (presumably because this is faster). The color when playing isn’t exactly right.
This is based off my memory…

FCP calls Y’CbCr “YUV”. YUV refers to an analog encoding scheme and is not the same thing as Y’CbCr, but (almost) everyone in the computer world calls Y’CbCr YUV. This is not important in your case.

B- When you import stills, FCP applies gamma correction. This is to convert the still’s sRGB gamma to match your video footage presumably.
The superwhite versus non-superwhite presets also affect how stills appear.

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what might be the best compromise approach?
The best compromise approach is to output your project and view it on your target audience’s displays (or just a few of them). I’m not kidding… this is advantageous because the real world differs from engineering standards (i.e. even FCP differs from engineering standards because of oversights/bugs).

[Bruce Greene]

Thanks Glen for the long and well thought reply. Unfortunately, you’ve pretty much summed up what I already know and practice (thought I actually use a sempte c sony crt that’s in pretty good calibration.

I guess, with computer monitors so easy to calibrate with affordable probes and software, I think we should be able to view the image in FCP on a calibrated and profiled computer display as a standardized monitor.

If photoshop can do it, so should FCP.

A good computer monitor plus a computer should easily be able to equal a 20,000 dollar calibrated LCD production monitor.

So, does anyone know what gamma FCP assumes the computer monitor is set to?

…

[Walter Biscardi]

[bruce alan greene] “I guess, with computer monitors so easy to calibrate with affordable probes and software, I think we should be able to view the image in FCP on a calibrated and profiled computer display as a standardized monitor.

If photoshop can do it, so should FCP.”

The problem with this train of thought is that FCP’s Viewer and Canvas images are purposely degraded because Apple assumes correctly that we all use external reference monitors to view our work. So if you truly want to know what your image looks like, you need to view it via an external video feed.

So calibrating your computer display for “perfect” NTSC color in the Viewer and Canvas will never quite work correctly because with degredation in image comes less than perfect color on the computer display. I never look at FCP’s displays when working with color correction, I only look at my external monitors or the scopes.

Walter Biscardi, Jr.
https://www.biscardicreative.com

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Bruce Greene]

[walter biscardi] “If photoshop can do it, so should FCP.”

The problem with this train of thought is that FCP’s Viewer and Canvas images are purposely degraded because Apple assumes correctly that we all use external reference monitors to view our work. So if you truly want to know what your image looks like, you need to view it via an external video feed.”

I for one, would not need a full res image to color correct. I think this approach is a legacy of the weak computing power when FCP was new. I think today, one should have the option to see accurate images in the canvas at the price of fewer realtime effects.

As the price of production hardware keeps going down, more and more FCP users will be less financially endowed and will use FCP for finishing their projects as it will be the only alternative. The requirement of a very high priced broadcast monitor and I/O card seems outdated to me.

And so does anyone know the answer to my question: What’s the best way to set up my mac/FCP today so that the canvas image is as accurate as I can get it?

[Kevin Monahan]

I don’t think it’s possible, or else many of us would already be doing this. I suggest you continue using your broadcast monitor until a proven monitor and technique comes out. Your computer monitor can’t display YUV or interlaced video, so this is the biggest problem for me. Why do folks want to do this anyway? Cut corners on cost, saving space on your edit bench or what?

Keep bangin’…

Kevin Monahan
Take My FCP Master’s Workshop!
fcpworld.com
Pres. SF Cutters

[Bruce Greene]

[Kevin Monahan] “Your computer monitor can’t display YUV”

My Sony broadcast monitor can’t display YUV either: It converts the YUV to RGB for display. Photoshop does this all the time as it converts into and out of LAB color space. I don’t think this is the problem. The challenge is that we’re thinking “the old way” is the only way.

I think this issue is becoming even more important as more content is watched on computer screens everyday. We should at least be confident that what we see in FCP will look the same on a properly calibrated computer screen elsewhere.

[Glenn Chan]

I guess, with computer monitors so easy to calibrate with affordable probes and software, I think we should be able to view the image in FCP on a calibrated and profiled computer display as a standardized monitor.

If photoshop can do it, so should FCP.

A good computer monitor plus a computer should easily be able to equal a 20,000 dollar calibrated LCD production monitor.
Photoshop does it because (for print work) the only way to get decent color is to profile all your devices and apply color management in the software.

2- The ‘affordable’/lower-end probes and software don’t do that great a job. see
https://www.drycreekphoto.com/Learn/monitor_calibration_tools.htm

3- If the monitor’s color gamut doesn’t encompass the color gamut of the output device, it will never do a perfect job. The software has to apply cheats to squeeze one gamut to fit into the other.

A computer monitor probably won’t perform as well as a reference-grade monitor. Regardless, FCP doesn’t implement any form of color management currently (i.e. it doesn’t do ICC, it doesn’t do 3D LUTs).

What’s the best way to set up my mac/FCP today so that the canvas image is as accurate as I can get it?
As I stated in my previous message, hopefully the iOne changes your video card’s LUT (look-up table) to get the desired gamma, grayscale tracking, white point (D65), white level luminance (35fL), etc.
White point: In print work, D50 is the standard for low-cost monitoring and D65 for higher-quality monitoring. For video work, D65 is the standard. 6500K is not the standard… it is a different color than D65.
Luminance: This doesn’t matter too much because almost nobody follows the standards here. In high-end facilities, you have facilities using a wide range of figures (i.e. 20fL, 30fL, 35fL). Part of this is because the largest Sony BVM-A can’t do 35fL without problems, so it’s best run at 20fL. Most consumer monitors are significantly brighter than the 35fL standard.
If you run a LCD, you should probably run it as bright as possible so you have less black level error.
If you run a CRT, white level should not be set via the video card’s LUT. Do it via the monitor controls.

Gamma: See
https://www.apple.com/support/shake/lbn/40/#Gamma
for information about how FCP handles gamma. Some of the information I stated previously about 0-255 versus 16-235 is incorrect.

The practical thing to do is still to get a broadcast monitor and/or check your work on your target displays.

[Bruce Greene]

Thanks Glen, your link to the shake info at apple helped a bit.

From the Apple support site:
Final Cut Pro assumes that QuickTime movies for codecs that support the YUV color space (including DV, DVCPRO 50, and the 8- and 10-bit Uncompressed 4:2:2 codecs) are created with a gamma of 2.2. This is generally true of movies captured from both NTSC and PAL sources. When you eventually output the sequence to video, or render it as a QuickTime movie, the gamma of the output is identical to that of the original, unless you’ve added color correction filters of your own.

However, during playback on your computer’s monitor, Final Cut Pro automatically lowers the gamma of a sequence playing in the Canvas to 1.8 for display purposes. This is to approximate the way it will look when displayed on a broadcast monitor. This onscreen compensation does not change the actual gamma of the clips in your sequence.

So FCP assumes that one’s computer monitor is set to gamma 1.8 (mine has been set to gamma 2.2 for viewing stuff on the web like the majority of web/windows users) and I incorrectly assumed that since NTSC and HD color is set to gamma 2.2 that I should match my computer display to that standard. But Apple has assumed I’m not that clever and made the conversion (in FCP only) automatic.

So, for now, I should set up a computer monitor calibration to gamma 1.8 just for FCP use D65 for the white point as the best compromise solution.

This however leads me to another question: Does quicktime make this gamma conversion as well? This is important as I want my QT files on the web to display correctly for the most possible viewers. If any application should be colorsync aware, it should be quicktime! Assuming all Mac computers today run at gamma 1.8 is a big mistake. Making the assumption in FCP and not in quicktime would confound the confusion. Not knowing what Quicktime assumes is even more confusing.

[Tony]

Bruce,

You are spinning your wheels trying to find a cheap solution to an expensive problem.

High end LCD which are considered equal to color grading CRT monitors are well into the 20-30K price range.

Such units incorporate look up tables. Ecinema or Cinetal are few companies that come to mind.

If budget is a concern you can do well with a AJA IO or other AJA video card to output your video signal to a PVM-14L5/1 or 20L5/1 multiformat monitor(s).

Along with a monitor probe which allows calibrating the gain and bias you will be able to set up the monitor accurately to do color correction work.

Calibrating the monitor to color bars via blue check is worthless if the gain and bias are incorrectly set up.

No one who is working in a critical color correction environment uses FCP viewer or canvas to make CC decisions so just give this thought up as it is incorrect for the intended application.

Regardless of what is possible in photoshop or any other application FCP can’t do this and I do not foresee Steve Jobs making your request an absolute requirement for FCP 6.0.

Tony Salgado

[Bruce Greene]

Bruce,

You are spinning your wheels trying to find a cheap solution to an expensive problem.

High end LCD which are considered equal to color grading CRT monitors are well into the 20-30K price range.

Spinning my wheels, yes. I cry uncle.

However, the “high end” LCD’s, from what I’ve seen of the Cinetal montior, it’s a good quality LCD housed in a box with a pc (kind of a windows imac). The PC is used only to adjust the color of the screen and provide i/o connections and sofware waveform/vectors and such. The monitor is kept in calibration using a $200 iOne probe from the pc world. It’s a very nice solution and for the right jobs, worth the money.

From my original post, I just wanted a compromise, approximate solution, to seeing something in the canvas that was ball park accurate and it got a little speculative from there…

That said, I still think there is no reason Mr. Jobs could not make the Final Cut Pro application color sync aware (like photoshop). It would be a great option for many users.

Thanks all.