Color Me Confused

It happens all the time. Someone gets a new camera or they switch brands or they switch raw converters: inevitably I get the “why are my colors different?” questions. Today I saw one newcomer ask if color saturation was impacted by exposure. 

bythom standardvneutral

Might be a little difficult to fully see the differences in Web-managed JPEGs, but that's Nikon's defaults for a Z6 on the left, Neutral on the right. Same exposure, same light, same everything else other than Picture Control.

The hint was in that third bit of the question (raw converters): color is not particularly determined by the image sensor, exposure, or even the camera for raw data. Color is all done downstream of the image sensor as you interpret the data that was captured. In the Nikon world, the Neutral Picture Control still produces pretty much the same result when white balance is set correctly when you shoot JPEGs. It doesn’t matter if you’re using a D3 or a D5 or a Z6 or a Z50, Nikon's Neutral Picture Controls produce remarkably similar neutral color, contrast, and dark-to-bright tonal ramp. 

Not that Nikon hasn’t made some small physical changes that might impact color in some way: over the years I’ve seen Nikon adjust the Bayer filtration in a number of different ways. The D5, for example, is more red sensitive at the sensor than the D850, for example. The D5 seems to have been tuned to produce low noise in indoor light situations. Likewise, Nikon has continued to trim and adjust their white balance preconditioning in the raw data, which has a small impact on color downstream. Black is no longer truncated to reduce noise.

Still, EXPEED set to the Neutral Picture Control on any Nikon camera tends to "correct" any of those low level physical changes. As much as people keep saying “the color’s changed,” I’ve not been seeing that since EXPEED arrived (we’re now on EXPEED 6). A Neutral Picture Control on any EXPEED-based camera produces a remarkably similar color delta when set correctly for white balance. (Sony users should note that Sony has made some changes to their underlying color model in BIONZ recently.)

Okay, some oldmansplaining: One of the tests us technical folk run is to shoot a known target (e.g. ColorChecker) under known light (e.g. measured Kelvin) and compare what the camera produced for each patch's RGB value versus what it should have. That’s called color delta. Nikon’s Neutral Picture Control has had a low color delta since it first appeared, and I can’t say that I’ve ever measured a Nikon EXPEED-based camera that is outside any expected statistical variance from another when shooting Neutral. I’m pretty sure Nikon designs Neutral to a fixed set of expected values.

Note that I keep writing "Neutral Picture Control." (Again, a Nikon thing. Substitute the appropriate Canon, Olympus, Sony, or other company's "neutral" rendering scheme if you need to.)

One thing that has changed over time is that the camera companies keep trying to make output more “pleasing” when a camera is used at its defaults. Pleasing tends to work like it did with film: more contrast, more saturation, and double-hue shifts.

Recent Nikon cameras have a new Picture Control, called Auto, and it's the new default. Oh, oh. Set that and some mad scientist in Tokyo has attempted to create an algorithm that looks at the scene you're shooting and applies color (saturation, contrast, and other) corrections to the data that Tokyo thinks you’ll find pleasing. If you compare an older Nikon EXPEED camera that used Standard as the default—which also had more contrast and saturation than Neutral, with a modest color shift—to a newer one that is set to Auto, you’ll definitely see differences as you shoot different scenes, all else equal. 

For JPEG work, I’ve long suggested Neutral or Flat on the Nikon bodies (and similar settings on other brands) if you’re shooting JPEG. Why? Because you’re going to end up with 8-bit data that’s  highly compressed. Editing color, contrast, saturation, and other “baked in” parameters back out when you post process is tough to do without creating banding or other issues. It’s far easier to add those changes in to a neutral, low contrast 8-bit data set than it is to alter things once values have already swung towards extremes. (Disclosure: I try not to shoot 8-bit JPEG unless a client requires it, as even 12-bit Compressed has a far better data set to adjust pixels during the editing process, and outputting JPEG from raw is pretty simple to do these days.)

So, if you shoot JPEG and you’ve followed my advice—particularly for Nikon who seems anal about making Neutral truly neutral—your new camera produces colors and contrast pretty much exactly like your previous one did. (Okay, there’s a small variation that might happen if you’re using Auto White Balance, or switch between third party and Nikkor lenses.)

Most of you reading this aren’t shooting JPEG, though, you’re shooting raw. So please understand and take to heart the following: the math and logic your raw converter uses will determine color, contrast, saturation, and far more. The raw converter, not the camera, determines how your raw image will look, always. When you shoot raw, your camera only captures data for you to later manipulate with a converter. Converters, too, have defaults. So any "wrong color" from raw files is your fault.

Moreover, things change in the raw converter world fairly often. Adobe has changed its underlying demosaic engine several times. Moreover, one source of recent complaints from Nikon shooters is that Adobe is now working with Nikon to produce raw conversions based upon camera settings (for the D780, Z6, Z7, and Z50). Those are coded into the EXIF as XMP data for exposure, highlights, shadows, luminance smoothing, luminance noise reduction detail, luminance noise reduction contrast, color noise reduction, color noise reduction detail, color noise reduction smoothness, sharpness, sharpen radius, sharpen detail, sharpen edge masking, contrast, saturation, and Picture Control. Note those last three. They pretty directly change color (though so do the other things and how white balance is set).

You asked for that, so why are you now complaining about it? Of course the color will look different, particularly if you left the camera’s Picture Control at the “all automatic” default ;~).

Aside: Adobe converters have for some time been putting unseen "exposure" adjustments into their converters, even before the latest XMP additions in NEF. I put "exposure" in quotes because that slider in Adobe (and other) converters doesn't actually adjust exposure. It changes mid-tone placement and linearity. 

I don’t want to get dragged too deeply into the technical here; Adobe’s integer-based conversion has a lot of limitations that can cause further issues. We’ll leave that discussion for another day, though anyone who's shot raw deep underwater will probably know what I mean. My point here is that even just a simple “Adobe default conversion” is now making a lot of decisions that didn’t used to be made with Nikon NEFs.

One reason why a lot of pros swear by CaptureOne as a converter is similar to the reason why I like Nikon’s Neutral Picture Control for JPEGs: Phase One software engineers try to push all raw camera captures to the same specific color assumption model. Technically, Adobe does, too, if you use Adobe Standard as the Profile, but Adobe's underlying color model tends to make for some small differences between cameras. 

It takes Phase One a bit of time to run each new camera through their process, but more so than any other raw converter maker I know, CaptureOne default conversion has tended to remain very consistent to their (Phase One's) “ideal” color, contrast, and saturation for any situation. This even applies across camera brands, for the most part. Thus, it’s unusual that I get the “my colors changed” complaint from a CaptureOne user. 

We're not done. Other issues come into play, as well. 

A few cameras ago Nikon split Auto White Balance—which most of you are using most of the time—into three distinct versions, only one of which tries to be color neutral. Yep, you guessed it, the default is "keep overall atmosphere," which means that it will absolutely skew warm. What you probably want to set is "keep white." 

At this point in my lectures I usually get the "so can I have your camera settings on a file, please" requests. 

You're still missing a point. There isn't a specific setting that is "right" for everything. Sometimes I want my colors to skew warm or cold, sometimes I want more contrast or saturation. Instead of setting your camera to a different (Thom's) default, you really should be setting your camera to your intent. That's true for raw shooters as well as JPEG shooters now that Adobe is picking up so many of the camera settings and many of you are shooting mirrorless (which is showing you the settings in what you see in the viewfinder). This is why configuring your camera, both initially and on the fly while shooting is one of the most important things you need to learn to do.

Final aside: Exposure first. Get the exposure set correctly for the scene you're capturing (in some cases when shooting raw, that may mean Expose To The Right, which you'll later adjust in your converter). As I've long written: start with optimal capture, and that begins with what is happening at the sensor, or exposure. Get white balance correct. Then and only then adjust things that change color downstream (e.g. Picture Control, saturation, etc.).

Short answer: If you're complaining about color but not changing any camera settings, the problem probably isn't the camera. 

This article has also been posted in Technique/Essays.

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