Using Strobes with Wet Plate: Discuss!

[StoneNYC]

So in the Nudes thread we were discussing using wet plate with strobes and how to go about it, it was however distracting and detracting from the nudes discussions. It was suggested someone start a new thread, so,.. Here it is!

So the main discussion was that wet plates exposure is so slow and it reacts mostly to UV light so it was mentioned that a very close 4800ws strobe would be needed as a minimum.

I asked if there was a way to push the plate so that a lower strobe like 2400ws could be used.

Ok I'm open to all ideas, please, any input is welcome

[ScottPhotoCo]

I was actually wondering if it might be similar to shooting Harman Direct Positive Paper as it shoots somewhere between 1-5 ISO. Might help get in the ballpark anyway.

Tim
www.ScottPhoto.co

[StoneNYC]

I was actually wondering if it might be similar to shooting Harman Direct Positive Paper as it shoots somewhere between 1-5 ISO. Might help get in the ballpark anyway.

Tim
www.ScottPhoto.co

I was told it was more like 0.25-0.5 ASA (I use ASA with film and ISO with digital, helps me keep them separate lol).

[cosmicexplosion]

What have you tried ?

[Sevo]

I asked if there was a way to push the plate so that a lower strobe like 2400ws could be used.

To do full motion (1/125s) shots - that was the other requirement made there! This would require speeding up wet plate by something like ten or twelve stops - flash takes some six out of the equation, but as flash heads are only made to a certain power, you cannot accumulate flash heads beyond maybe two more stops (four heads in place of one - past that they'll need more extra distance than they gain in brightness), so there still are four to six stops acceleration needed. Which is a lot.

So far a gelatin base is absolutely mandatory to get to film speed, and the known sensitizers for gelatin silver have no sizeable effect on collodion silver emulsions. While it would not be against the laws of physics and chemistry to accelerate alternative processes, the research effort would not be smaller than that that went into gelatin film - so it would be way beyond our means to do from scratch as hobbyists. Has anybody here found patents on the gelatin free process materials many large process film makers had been dabbling in in the late eighties, before direct-to-plate laser printer lithography broke through and killed all work into that direction? There might be at least starting points on the search for suitable sensitizers in there.

[Fourtoes]

i've only tried it in one session. I had a Bowens Quadmatic with a 2000 head. Plate was underexposed by about two stops. Moving the heads much closer did help but they were still underexposed, and I dont like the idea of a flash bulb exploding in someones face at that distance. So I reckon 4000W is do-able but thats right up in your face. So the more flash you have the better.....

I'll stick with a constant light source for now.

[Lachlan 717]

What about black lights? Aren't they UV?

[Sevo]

What about black lights? Aren't they UV?

Sort of. They are deep violet to nearest UV-A. But they filter out the UV-B that would have most impact on the plates, and lose 95% of their output over that, so that you'd need more of them than of regular daylight FL tubes. Process plate illumination tubes and the like better should not be used on human subjects due to their hard UV-B spectrum (unless the model is willing to risk skin cancer for a photograph) - the best compromise would be tanning bed tubes, if you want to optimize artificial light intensity.

[Doug Howk]

I believe Michael Schindler uses strobes. Check out

[goamules]

Can you put a 250HP Mercury outboard engine on a 16' Old Town Canoe? Perhaps, but it's not going to be easy and it's not what it was made for. Seriously, there was one person on another forum that got some pretty fast wetplate exposures with strobes, I'll have to hunt around for who it was. Typically, we say wetplate is about ASA 1-3.