Let’s say you’ve just made a print of your latest image, but how do you know what it -really- looks like?

You would not take a flashlight and cover the end with blue cellophane, and shine it on the print, because it would trash all the other colors. To get a more rational view, you might take it outside and look at it in the sunshine, which has a balance of all the colors, right?

As a print-maker, you want to have a lightbulb you can use indoors that shows all the colors evenly (unlike the blue flashlight) and thus similar to sunshine.

The color temperature of sunshine is agreed to be about 5000K. Lower temperature is “warm” (making white paper look orange-ish) and higher is “cool” (making white paper look bluer).

But besides the color temperature, sunlight is also a reference to all the colors in balanced amounts. How close any lightbulb comes to that even balance is the bulb’s CRI, Color Rendering Index. By definition, sunlight’s CRI is 100. Fluorescent bulbs usually have a CRI of 80 or less, while specialized bulbs can get to 95 or more. 

Unlike sunlight, all bulbs have a spectrum where some colors have more energy than other colors. Fluorescents, for example, exaggerate the green and orange dramatically, and the emission graph looks like a saw tooth blade. Most LEDs peak in the dark blue and greens. Sunlight however has no peaks or valleys, and is a smooth, nearly horizontal graph. 

Fluorescents and LEDs have low CRI, and so you are seeing exaggerations of some parts of the spectrum and a muting of other parts. No good if you’re trying to analyze a print.

Generally speaking, any CRI above 93 or so is suitable for viewing photos, but the closer you get to 100, the better. Such bulbs are usually expensive, often in the $20-$40 range. Solux “museum” bulbs were 4700 K, about 94 CRI and $30 each.

All that leads here: I have found standard base lightbulbs, with 5000K temperature, and a CRI of 98 (which is amazing) and furthermore are LEDs, using less electricity than halogen or tungsten.

AND… they are less than $3 each. 🙂

So I’m sharing what I use with all the photographers I know. You can buy them on Amazon. Here is the URL:

https://www.amazon.com/gp/product/B0BNBN5TY4/

Finally, if you’ve never had such a light before, it will take 2 or 3 days for your brain to adjust to it. As my drill instructor used to say “Suck it up sweetheart. You’ll get used to it.” (For you cynics: no, I do not benefit from this recommendation. It’s entirely altruistic.)