Q I’ve been struggling with trying to get a handle on how things look in various situations. I look at something when I’m shooting and have an idea of what I’m getting, but then things seem to go south once I start editing. When I have the opportunity to use a camera that gives me RAW or some sort of flat output, I still look at the output through the sort of pseudo-video output that’s available so I can see what’s going on and make adjustments, but it seems to depend on what monitor I’m looking at. Now I have a colorist who wants to give me a LUT to use while shooting. I’ve gone from somewhat confused to very lost. Should I be using a LUT to help?
A Well, even though you feel lost, I congratulate you on admitting there’s a problem. Too often, problems like this are waved off as either "it’s just the way it is" or "don’t worry about it, we’ll fix it later." But you’re trying to get it right.
You might have heard terms like linear and nonlinear. Basically, if something changes according to a linear scale, there’s a one-to-one relationship. The speedometer in your car is a linear scale. If you’re going 20 mph and you double your speed, you’ll go 40 mph. Doubling the speed works the same way whether you go 10 mph or 30 mph.
The aperture on your lens is nonlinear. If you’re at T/4 (or ƒ/4 for a still lens) and want to reduce the light hitting the sensor by one half, you don’t go to T/8, you go to T/5.6. Mathematically, T/4 to T/5.6 is a change of 1.6, but if you want to affect the same change from T/11, you’d go to T/16—a change of 5.
Now you may think I’m going to apply this linear versus nonlinear example to a discussion about LUTs or RAW capture or just displays, but I’m not. I want to apply it to the whole production process. I’m not referring to a discussion of technical standards for workflow, but rather how much focus and effort relate to image quality in all aspects of production, postproduction and delivery.
If you really think about it, we’re quite nonlinear about image quality in our craft. Consider how much energy is spent in discussions of Bayer filters, native ISO, dynamic range, rolling shutter, HD, 2K, UHD, 4K, 8K, frame rate, sensor size, lensing, etc. The web is filled with camera tests—shootouts in daylight, tungsten light and almost no light. Forums are roiling with dynamic range and RAW vs. Log capture discussions.
Don’t get me wrong, this activity is great. It shows people’s passion and dedication to improve their craft. But it would be great if that passion and energy continued through the whole production chain—including displays and calibration.
There are pages and pages on camera "X" and camera "Y," and rig "G" and rig "H," but many times, displays are relegated to accessories or camera support, or they’re missing completely. It would be great if image display was also at front and center.