Exposing paper with electronic flash

[baachitraka]

Instead of an enlarger bulb, will paper respond when exposed using electronic flash, triggered remotely (by darkroom printer)?

 

[Svenedin]

Are you wanting to “pre-flash” the paper before enlarging an image normally?

 

[baachitraka]

No. Just an idea. Will replacing enlarger lamps with electronic flash, do the job of exposing the negative on the paper?

 

[baachitraka]

Yes, controlling is bit hard if at all possible.

 

[mmerig]

You'll have to have really fast hands if you want to dodge or burn-in while printing, and that's assuming that the usual flash duration is long enough to expose slow papers, which are much slower than film.

 

[baachitraka]

Actually a dual setup like in studio flash. One of exposing and other of modeling...

Okay, not a great idea I think.

 

[ic-racer]

 

[tezzasmall]

Maybe no good for enlarger exposures, but I have read in the past of people using the flash for numerous flashes to take a photo using a camera with photo paper in it for a negative.

Terry S

 

[Mainecoonmaniac]

Instead of an enlarger bulb, will paper respond when exposed using electronic flash, triggered remotely (by darkroom printer)?

You'd have to really fast with burning and dodging.

 

[tedr1]

Some method is needed for the attachment of variable contrast filters in front of the flash.

 

[Svenedin]

Surely this could only have any chance of working for contact prints. How would you focus an enlarger if you had somehow replaced the lamp with a flash? I also not sure why you would want to do this.

 

[RalphLambrecht]

Instead of an enlarger bulb, will paper respond when exposed using electronic flash, triggered remotely (by darkroom printer)?

Yes,as long as the light intensity is sufficient but, depending on the flash duration, you may have to deal with reciprocity issues because, some flash durations are too short.

 

[baachitraka]

Surely this could only have any chance of working for contact prints. How would you focus an enlarger if you had somehow replaced the lamp with a flash? I also not sure why you would want to do this.

Just like with studio flash, this imaginary device may have a modeling lamp. But I see it all together it may be too difficult to work with such a device.

 

[MattKing]

I could see this working if your exposure was made up of multiple flash exposures.
But the type of reciprocity failure we don't encounter as often - exposures that are too short - might be a real problem.
It might also be really irritating!

 

[Chan Tran]

Minolta and Beseler have done it a long time ago. The system has pro and con. The 45A uses 4 flash tubes I think and I think the bulbs went bad quite often.

 

[EdSawyer]

The 45A is the best color head ever made for the Beseler 45, IMNSHO. I have 6 of them (using one, the rest for spares). They are extremely sophisticated, and highly regarded. They use 6 flash tubes total I believe. They last quite a while, years usually. They can be hard to find in the secondary market, but not that bad really. If anyone needs the instruction or service manuals for them, I have them all posted online.

 

[baachitraka]

How do they work?
- Main exposure: 10 pulses of during 1/1000
- Burning: 5 pulses of during 1/2000

For paper, how do they respond for the continuous pulses of short duration?

 

[chromemax]

This is a 6x6 cm negative enlarged on 8x10 lodima paper using a flash as light source.
The flash, a fairly small Metz 30 BCT4 flash (NG = 30), was arranged inside the light bulb space of a Durst M805 condenser enlarger. Obviously the light bulb was removed after the negative was focused and framed in the easel.
Because the lamp of the flash is smaller then light bulb, for a better light diffusion I arranged a square of Lee 250 (Half White Diffusion) beteween the electronic flash and the mirror inside the enlarger head, but despite this a lighter area in the lower left corner may be noted. The flash was triggered using an external switch; I do not remember how many times the flash was triggered for a correct exposure on this very slow paper, it was a two multiple, maybe 16 pulses. The iris was 4 or 5,6, I'm not sure, sorry but now I'm away from my notes.

 

[Svenedin]

This is a 6x6 cm negative enlarged on 8x10 lodima paper using a flash as light source.
The flash, a fairly small Metz 30 BCT4 flash (NG = 30), was arranged inside the light bulb space of a Durst M805 condenser enlarger. Obviously the light bulb was removed after the negative was focused and framed in the easel.
Because the lamp of the flash is smaller then light bulb, for a better light diffusion I arranged a square of Lee 250 (Half White Diffusion) beteween the electronic flash and the mirror inside the enlarger head, but despite this a lighter area in the lower left corner may be noted. The flash was triggered using an external switch; I do not remember how many times the flash was triggered for a correct exposure on this very slow paper, it was a two multiple, maybe 16 pulses. The iris was 4 or 5,6, I'm not sure, sorry but now I'm away from my notes.
View attachment 189650

Nice picture but what does this method achieve that is not achieved by using the enlarger in the conventional manner?

 

[MattKing]

Nice picture but what does this method achieve that is not achieved by using the enlarger in the conventional manner?

It is printed on Lodima, which is a very slow contact paper. If you try to print using conventional light sources, the exposure times are loooong.

 

[chromemax]

Nice picture but what does this method achieve that is not achieved by using the enlarger in the conventional manner?

Lodima paper is so slow that it is impossible to use this paper with conventional enlarger: the exposure time should be so long and the heat from the lamp so high that the enlarger would be damaged.
It was an attempt of using cloride paper with small format negative, it can be do but isn' t s so practical for all the things reported in the thread (no dodge and burn, impractical focusing and framing, etc)

 

[baachitraka]

The imaginary enlarger should have modeling lamp ;-) and electronic flash. So that will help focusing, framing, etc.

 

[M Carter]

Done it successfully. And I recently got a Rodagon-G lens and I may return to it for large prints. Here's what I've learned:

I started down this path with a condenser enlarger. I wanted to dupe some 35mm experimental shots onto 4x5 velvia - the lab laughed, said it couldn't be done. Nothing gets me motivated like that.

Enlarger at the time was a 67C - front door slides out to expose the bulb and filter drawers. I made a black foamcore replacement door, taped a small camera flash to it so the flash illuminated the light bulb, not the condensers. Basically I made an extremely fast and bright light bulb. I used lighting gels in the filter drawer to adjust color balance, and ND lighting gels to bring exposure down. I also verified that the flash was consistent with a light meter. I used a PC cord and momentary button to trigger the flash, later used my radio slave. I used 4x5 polaroid to check color before going to film, bracketed a bit, and held back film for slight pushes.

For printing paper, I did some rough experiments, but basically used a full CTO gel in the filter drawer to get the light into the tungsten range.

For very large prints, you can set things up so it may take multiple flash pops. Chances are, you'll need film-plane masking for dodging/burning - if you're not up for that, you need to rig up something like a frame over the paper, where you can replace dodge/burn cards to return to the same place with each print. Then dial it in, like - 2 pops base exposure; 1 pop with mask A, 2 pops with mask B an so on. Fine tune individual pops with a good quality ND filter under the lens. Chances are you have 1-stop lying around, grab a half stop, or for minor tweaks use a clean lighting gel, which can be found in 1/4 or 1/2. If you find one exposure needs a half stop adjustment or something, use the F-stop and re-calculate all the other pops.