Zygomatic Color

Casual color management in the consumer-land


Categories: Blogs Tags: Spectral World

What all you need is a 30 USD dichroic halogen lamp, may be

In short:

In long:

A dedicated PC, a dedicated room, a light booth, a spectrophotometer, etc. Strict color management requires such instruments. Do you want to buy everything? OK, stop reading this article, ask for X-Rite, and pay 100,000 USD.

I guess you don’t want to pay even 100 USD. Let’s spend wisely for casual color management in the consumer-land.

Before buying a ‘solution’

There are many ‘solutions’ in the market which claim fancy numbers like ΔE. Before considering the meanings of those numbers, we should consider total optimization. The strength of the chain is in the weakest link. We should always focus on the weakest link.

The colors come from somewhere and turn into your products. In many cases, they come from your clients as sRGB or Display P3 image files. In some cases, you take photos, scan something, or draw images. Your products are printed things while you are interested in Zygomatic Color.

In casual color management, usually, where is the weakest link? Printers. Zygomatic Color helps you about them. When your printer is enforced? This is the question.

Don’t trust, verify

In the viewpoint of strict color management, the next weakest link is your display. Caveat: When strict color management says ‘display,’ it always contains the room where the display is installed. Replacing a ‘display’ means tweaking a room. In common senses, your room is the next weakest link.

I don’t recommend tweaking your room. It is never a good value for the cost. There is a better way for you: Unreliable display.

You should be familiar with unreliable narrators in many stories. They often tell blatant lies, but the narrated stories make sense for the most part. We can distinguish the lies from reasonable stories. Sometimes the distinction is impossible or subjective, and this is the charm of fiction.

You can treat your display like the unreliable narrator. Learn mannerisms of your display. Verify it by your printer (calibrated by Zygomatic Color).

One more problem: Gamut. The iPhone has a wide gamut display and cameras. Many printers have wider gamuts than sRGB. Can you live without a wide gamut display? Yes you can, as far as you can live with an unreliable display. Usually you can find some nuance of out-of-sRGB colors in Photoshop. You should verify out-of-sRGB colors by your printer, of course.

Even if you consider buying a color management display, I don’t recommend wide gamut models. It practically requires a dedicated Windows PC (macOS is another story), because many Windows apps assume a sRGB display without color management. Such apps show the wrong colors to a wide gamut display with color management. I think this is a serious defect of Windows. Just convert the colors of such apps! But at the moment, it is difficult to use such apps with a wide gamut display. On the other hand, a sRGB color management display can do everything except action games.

(BTW laptops dedicated for photo editing make sense. If you want a wide gamut display, consider laptops.)

Buy a dichroic halogen lamp

No matter how you are frugal, you need a good illuminant. Even if you use it just for viewing your products, you need it. Fortunately, the best one is free: The sunlight. But if you work at night, or you need a very stable illuminant, the sunlight isn’t for you. In such cases, you definitely need to enforce the link by spending your money.

There is a sad fact: High CRI LEDs are not enough. If you don’t need very accurate color, high CRI LEDs are excellent. If you do, CRI 95 is not enough. You can clearly find the difference between a CRI 95 LED and a dichroic halogen lamp. Even for casual color management, CRI 95 is OK, not fine. You can manage to do with it. But I recommend you to buy a dichroic halogen lamp. It is 30 USD including a clip lamp holder.

Do you need a camera besides you have an iPhone?

Once you have enforced your illuminant, the next is your camera. Never reverse the order. Camera is less weak link than illuminant, in most cases. But a paradox is here. Xenon flash is an excellent illuminant, but it requires an expensive camera.

Xenon flash has a lot of virtues. It is stable. It makes little heat. The light contains much UV which excites fluorescent agents.The color rendering is perfect. But built-in flash isn’t for you, because it makes noisy reflection on the object. External Xenon flash is for you. And it requires a hot shoe, which phones never have and many point-and-shoot cameras don’t.

So the budget might be bigger than you wish. Under 500 USD for the total system is hard to achieve, I guess. “Oh no, I’ll stick on my iPhone and dichroic halogen lamp,” that’s a good decision.

If you go to a camera and Xenon flash, there is good news and bad news. Good news is a secondhand camera is enough for you. Don’t pay a premium price for a new one. Bad news is we cannot know which is the most colorimetric camera. The problem touches quite deep esoteric information.

A tunable light source (wavelength variable monochromatic light source) is absolutely necessary for measuring colorimetric performance. About some cameras, we can find measurement results in scientific articles. But the information is too sparse to know the best one. A tunable light source is 20,000 USD. No hobbyist has such a thing. DxOMark makes public Sensitivity Metamerism Index of many cameras in their site, but the meaning is questionable. Anyway I don’t trust any results without a tunable light source. In addition to that, lens coating often absorbs near-UV and near-IR which image sensors can be sensitive.

The bottom line is, I weakly recommend Canon. But if you already have another camera with a hot shoe, don’t replace it before you find any problem.

Scanners in all-in-one printers are… um…


I regret to announce you: Scanners in all-in-one printers are not for you. You need a discrete photo scanner if you need accurate color.

Zygomatic Color depends on flatbed scanners at your hands. All-in-one printers are everywhere, but discrete photo scanners are uncommon. I wish all-in-one printers were enough for Zygomatic Color! No, it isn’t. C’est la vie.

If you never had any experience with a discrete photo scanner, try it. The difference is astonishing.