A Darkroom Safelight Headlamp

A friend showed me the wonders of a safelight headlamp and I was hooked. The light is always where you need it, and nowhere else. Some headlamps include red LEDs, but the main light is usually a powerful white LED that would be disastrous in the darkroom, even if you cover it with a safelight filter.

I found a cheap rechargeable headlamp that included red LEDs: “COSMOING Rechargeable Headlamp, 500 Lumen Ultra Bright Head Lamp 5 Lighting Modes...” (This same design is sold under a few different names in 2024, so it should be available from many vendors.) It’s cheap, small, and the UI is reasonable (has too many modes, but “mode memory” remembers the previous mode when you turn it off and on.)

The Hack

It comes apart easily with no hidden fasteners. First, simply crush the white LED emitter with wire cutters. Poor thing! This makes the UI difficult because the white LED modes are now dark. I added a jumper between the base pins of the 2 transistors so the red LEDs activate instead of the white one. Now every mode is a red mode, and I can choose from 3 dimming levels. Nice!

It seemed like the red emitters in this headlamp were a little more orange than I wanted, so I cut tiny squares of Rosco #27 lighting gel to cover them. This filters out the wavelengths higher than about 580 nm which seems good enough for me. You shouldn’t shine this right onto your film at close range for very long, but it didn’t seem to fog motion picture print stock (single digit ISO) when used at low dimming settings for about 5 minutes. (It’s safer to bounce any safelight off the ceiling, so that’s a good option for this headlamp too.)

Further Research

Kodak’s How Safe is Your Safelight (pdf) has lots of good advice about safelight color, distance, and timing considerations.

I only need the headlamp for spooling down and loading orthochromatic motion picture stocks, but if you’re judging exposure you might prefer an amber safelight for some materials. LEDs come in lots of colors, so maybe you could swap the white LED for an amber one of the correct wavelength?