I’m getting older, losing my near sight, and the world is growing dim. Sounds dire. And while it may be true, I think a big part of my problem is the light bulbs in my shop. Unlike most of you, I have a photographic record of the lighting in my shop. I recently compared photos I just took with photos I took several years ago. There was a noticeable difference. My shop is lit with long lasting compact fluorescent light bulbs. These things may last a long time, but their performance degrades significantly over the course of a year or 2. You can see this by installing a new bulb next to an old one. Light bulbs have 3 characteristics we need to know about:
Color temperature, expressed in a temperature in degrees K , is the color of the light. Generally, incandescent bulbs are yellower (we call them warmer). Fluorescents are bluer (colder). The color of the light isn’t a huge issue for us. All you need to know is that if your shop is lit with fluorescent bulbs as mine is (and most shops are) colors may change when your work is moved to natural light or incandescent household lights. I think the color temperature remains constant over the life of the bulb.
Color Rendering Index (CRI) is the percentage of the total light spectrum a bulb produces. CF bulbs typically don’t produce as much of the spectrum as incandescents do. This is what most of us don’t like about fluorescent light. They reduce the color of everything they illuminate.
Lumens is the measure of how bright a light is.
Fluorescent bulbs significantly lose CRI and Lumens over time. Perhaps I shouldn’t wait until these things burn out before I replace them. In my State, the big box home centers have collection points for used CF bulbs. If you’ve had CFL bulbs in your shop for a while, perhaps you should consider refreshing them.