Using the Color Checker Classic

Hi all,

I've got a Color Checker Classic - non legacy - and I tried using it in DR but I get poor results. White Balance adjusts fine - though I'm now balanced in camera so I don't really need it - but the colours end up a bit weird. The multimeter on the right for example, the red button is now excessively saturated. And the overall black level is elevated.

I appreciate there are quite a lot of variables - and a screenshot might not translate well on your end.
My monitors are calibrated.

The footage is from a Sony ZV-E10, REC709. I tried a few options but I always end up with similar results.

Any pointers/ideas?

Thanks!

In my experience the auto set with chip charts over saturates causing artifacts. I need to match hue vector but keep saturation about halfway to the box, not all the way out there.

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Thanks.

It's a shame as I don't think I can use the colorchecker with the vectorscope - the patches are not standard. Unless I am mistaken, does anybody have a process to use the ColorChecker classic?

It's a shame as I don't think I can use the colorchecker with the vectorscope - the patches are not standard. Unless I am mistaken, does anybody have a process to use the ColorChecker classic?

All of these charts are only ballpark at best, and they're going to vary wildly if the color temperature on set isn't predictable and set in the camera. (In other words, mixed lighting will make the process go crazy.)

The Color Checker Video is closer, but even that's not quite right. None of them can get right in the "boxes" for vectorscope. I think 50% is even where the DSC charts go.

I find for the video chart, the hue vectors are close, and the rest you have to approximate. Unless you use a really well-calibrated chart (which the Calibrites are not), there's a bit of guesswork involved.

Using the right camera color science and at least a grayscale chart can yield reasonable, ballpark results. If you know what peak white is, and what black is, and what middle gray is, you can kind of reconstruct the rest. Where the color biases are depends on the camera. The Sony ZV-E10 is a very modest ($600) still camera that can be used for video -- I would consider it kind of Rec709-ish and just get the gamma curve right and balance the rest by eye and by scopes.

Thanks Marc,

My lighting is fixed, I have two Nanlite studio panels - I also have fluorescents on the ceiling and a window but I did my tests when dark. I have indeed set the white balance in camera - that's definitely a good starting point as you suggest.

Happy to leave the colours as they are - my "productions" are not professional. I had that colourchecker already and I hope it would "magically" improve things for me!

If not mistaken, the colourchecker classic doesn't match the vectorscope so I cannot use it manually - I would need the colourchecker video for that - but I'd rather spend the money on something else!

I am though interested in getting the gamma curve right - do you happen to have a link or a document on how to do that?

Thanks!

I hope those fluorescent lights were off too, they can be very nasty!
I second what Marc wrote, those color charts are not worth the effort for an automatic process. Even an expensive DSC chart is not hitting the targets all the time, you'd be surprised how different even high-end cameras can be (interestingly, the iPhone gets close). All charts should be printed at 50%, since you can't get 100% from a reflective chart. That's why we have the 2x zoom for the vectorscope.
The gamma curve depends on the profile you set in the camera. If you want to check it a grayscale is good enough, and in this case you can use those made for stills cameras. But since most current cameras have far more DR than your final display, how you are using the available range will be an aesthetic decision just as much as a technical one.

Thank you Uli,

No, the fluorescents were not off and I am actually thinking of trying without them - though it would likely mean that I would need to add more studio lights which I am not sure I am prepared to budget for right now.
I've just replaced the fluorescents with "daylight" ones (I used to have warm white ones, with the studio lights to match), so at least when some brightness comes through the window it's roughly the same colour temp!

I get it about the colour checker and other charts then, thanks for confirming. I won't waste time on that.

And good point about DR of the camera. Because I am using REC709, the decision is made by the camera I guess - alternatively I should shoot in SLOG - which is another step I am not ready to make at this point, my videos are about electronic repairs, nothing fancy! Green boards

That said, can I use my colourchecker to play with greyscale?

That said, can I use my colourchecker to play with greyscale?

Sure, why not?

Regarding fluos, there are D65 ones which are pretty close to daylight, they just don't come as cheap as what the caretaker puts in the corridor
They are used in film lighting, like Kino Flo.

Osram.jpg (248.21 KiB) Viewed 507 times

The Osram Dulux L seems to have a >80 CRI, the tubes I've installed claim >85. I think they measure more around 5000K but better than the 3500K I had before My Nanlite can be adjusted so I matched the colour temp to match.

With white balance adjusted (using the grey patch of my colourchecker) I see much "paler" colours than before. Is it normal to have different skin tones and general colours depending on the colour temp of the lighting - and assuming that everything is white balanced? Sorry, I'm sure this is a newbie question, isn't it?

Regarding adjusting gamma, you don't happen to have a link that could help me? I had a look online but so far I couldn't find much.

Thanks!

Dulux is just their brand. These ones are from Kino Flo lights, and the 95 stands for a CRI of 95.

Which profile do you shoot in the Sony? Regarding getting into grading, aka making your pictures look nice try this: "DaVinci-Resolve-18-Colorist-Guide.pdf" (free from the training area).

some basic facts re: lighting, meters, filters, etc.
daylight = 56k not 65k. 5,600 kelvin
tungsten ( film lights not lamp bulbs on your desk ) = 32k ( 3,200 kelvin)

full CTO = color temp orange = adjust daylight to tungsten ( from 56k to 32k )
look up 4' rolls of color temp correction from roscoe or lee ( google it ).
full CTB = color temp blue = adjust tunsten (32k ) to daylight ( 56k ).

there is a loss of fstop when using any filters ( less for cto and more for ctb )..

meters: color temp meters like minolta color meter
spot meters: for reading grayscale cards ( reflective)
ambient meters: for reading overall zone 5 reading ( like in your camera meter).

kino flo lights come with little barn door-like flaps on them, which are used to kill spill and also to attach filters and diffusion as needed.

HMI's are 56k and used with square wave ballasts to eliminate flicker
Tunsten is 32k
outdoor light is 56k IN GENERAL. Different times of day ( like early morning and late afteroon ) will warm up the light due to the light going through more atmosphere.

color temp meters must be professionally calibrated about every 2-3 years ( or compared with another one on set ... like the DP would have one and the Gaffer would have one, and they would look at what they got on the meter and if it was the same they would say, " oh goodie ! "

Well, according to CIE daylight is 6.500 K, the so-called standard illuminant D65.
But you are right, in opto-chemical photography it was usually defined as 5.600K. Anecdote has it that a guy from Kodak's lab was sent out of the door on a sunny day around 10 a. m. to measure it and came back with that value
Digital cameras are normally designed for a 6.500 K color temperature.
What natural daylight really is depends a lot on the position on the earth and the composition of the atmosphere, plus the time of day.

I think I have the same micrometer you have. interesting. I'm wondering....what happens if you have a white ceiling in that room and you point a 1,000 watt tunsten light at the ceiling and let it bounce back down as a diffused light from above you to the stuff you're working on... ??? It would take about 7.5 amps fuse to do it but for safety sake film people generally think 10amps per 1,000 watts. So one light might do the trick for you and if you just close the blinds to outside it will overcome the daylight that comes in through the cracks...it won't matter.

p.s.
that would mean you set your camera wb to 32k for tunsten.

The Nanlite Mix Panels go all the way from 2.700 to 7.500K.

Dulux is just their brand. These ones are from Kino Flo lights, and the 95 stands for a CRI of 95.

Thanks. I might make my own DIY ones

Which profile do you shoot in the Sony? Regarding getting into grading, aka making your pictures look nice try this: "DaVinci-Resolve-18-Colorist-Guide.pdf" (free from the training area).

I have profile set to "off" at the moment on my E10.

More than color grading I'd like to do some color correcting - but I guess the tools to learn how to do that are the same.

I am "familiar" with the controls, I have been into photography for a while and I normally tweak my pictures with Lightroom. I know what each of those controls do - what I'd like to learn is "how to use them". It's like the difference between "I can use pencils" and "I can make a drawing"

I'll take a look at that document, thank you!