Howdy gang!

I've spent the last couple of days trying to get a handle on artifical lighting for a Tintype studio or for lighting a "set" at someone else's location.

I find f16 @ 1/2 Second works good in bright sunlight, which is about 1354 Watts per square meter. Tintype is shortwavelength sensitive and insensitive to longer wavelengths.

I want to keep exposure times to 1 Second or less and depth of field isn't critical for studio work, so I can likely increase exposure by maybe 4 stops over the f16/.5 which would bring me down to 169 Watts per square meter.

Now, if my set is 3 meters wide by 2 meters high, I need about 1KW of blue-rich light evenly spread over the set. Allow 1500 Watts for inefficiencies, overlap, and what-not.

Do I have that right?

Quartz halogen seems to have the best blue-rich spectrum but mercury vapour gives nearly all it's energy in the wavelengths where tintype is most sensitive, so it would generate less heat on the set.

This is kind of a wierd puzzle since I am not worried about colour balance or "natural" colours but simply getting enough illumination in the blue-to-UV range. For nearly 40 years I have simply used flash and strobes but that doesn't work with tintypes.....

Whatever I do for lighting needs to be portable and not overly expensive.

Thoughts? Ideas? Suggestions?