Wet plate / artificial lighting

[cyrus]

Yeah in looking over the redheads it doesn't look like it is worth the effort to modify them to take mercury lamps - I WAS thinking of just removing the old sockets and installing new ballasted sockets. But everything I've read says collodion requires a massive flash pop (9600!) and with my f/9 process lenses, that's not practical. Similarly, the regular CFL and tube flourescents seem to only work if you use massive banks and place them really close to the subject, according to what I've distilled from the discussions. So I think, theoretically speaking, mercury vapor lights are the most effective way to go, including and probably especially mercury vapor UV lights, the sort that are used in dance clubs. Now, does this create a natural looking skin tone on collodion? Who knows!

[Sevo]

mercury vapor UV lights, the sort that are used in dance clubs.

While technically mercury vapour, these are generally called "fluorescent light" - "mercury vapour" is usually only used when talking about high pressure discharge lamps, as these come in a fairly wide variety of different discharge media...

Black lights as used in dance clubs are filtered to be low power and half near UV, half visible deep blue so that they cannot cause eye or skin damage - their energy in the UV spectrum is modest, not significantly higher than that of daylight FL tubes of identical wattage.

[BarryS]

Cheap spiral CFL bulbs leak UV like crazy. I use a couple of Fotodiox C-1600 fixtures with a 4x4 grid of edison sockets. I fill them with cheap contractor-pack 26w daylight CFLs. With two units, my wet plate exposures are very fast.

Process lenses for wet plate studio work make no sense at all--you're better off hunting for a fast old portrait lens--they're not all expensive. An f/4 or f/5 lens will only need a quarter of the light of your f/9 process lens.

[Jason Greenberg Motamedi]

In the past when I need small I built lights based on four 55w 21" 5500k fluorescent bulbs from an aquarium supply, but these weren't so cheap, and the Fotodiox uses twice as much power. If course, this might not equal twice as much light, but still, it looks like a nice product. How is the finish on it Barry?

Sometime back I adapted a 1K Mole Fresnel and plugged in a 4800ws Speedotron head. The result was disappointing, as I lost nearly a stop of light compared to a 22" beauty dish. I have a few more of the 1Ks and had thought about putting in a Mercury bulb, but this convinced me the effort would be wasted.

[cyrus]

Process lenses for wet plate studio work make no sense at all--you're better off hunting for a fast old portrait lens--they're not all expensive. An f/4 or f/5 lens will only need a quarter of the light of your f/9 process lens.

That's fine advice for an LF and smaller camera, but try finding (and paying for) an f/4 or f/5 lens for a 20x24 camera, not to mention have that camera front standard support a 10-20 lb lens! (That is where I'm going with this - see if I have a ULF camera built I don't want to be limited to only being able to use it outdoors or next to a window. If I can't find adequate indoor artificial lighting, then such a camera will be a white elephant for me)

But in any case as far as I've seen the report on various discussion formums, even the use of CFLs with a fast lens requires a min of 20 sec exposure and/or very small distance from the subject to the light.

Now here's something worth trying...
Eliminator EBK-400 Black-400 High Powered 400 Watt Blacklight

[cyrus]

While technically mercury vapour, these are generally called "fluorescent light" - "mercury vapour" is usually only used when talking about high pressure discharge lamps, as these come in a fairly wide variety of different discharge media....

THIS looks a lot like a HID mercury vapor bulb not a fluorescent bulb. Am I right?

[E. von Hoegh]

Thanks Jason. I was thinking that there are industrial mercury vapor bulbs/fixtures that I can use and which are cheaper than those for the photographic maket. The spectrum for mercury vapor lamps seems to have a large spike for UV beats the pants off of flourescent.

Look for old outside lighting fixtures that take MV lamps.(And have good ballasts)

You'll need to diffuse them, but you'll have oodles of light. Make sure your diffusion material is UV transparent.

The tanning bed tubes are a good option as well.

[E. von Hoegh]

THIS looks a lot like a HID mercury vapor bulb not a fluorescent bulb. Am I right?

NOT a flourescent.

[cyrus]

Didn't think so - worth investigating?

[Sevo]

THIS looks a lot like a HID mercury vapor bulb not a fluorescent bulb. Am I right?

Probably - looks like a high-pressure street lamp. But the UV output should be very limited unless these ones are some illegal high-risk device. Approved stage or club blacklights are supposed to be UV safe, and most of the light would vanish in the filter glass.