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  1. #1

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    OK I'm at it again...... I just made a palladium print (and a nice little print it is) using a strobe head in a 24" reflector, now the total exposure with recycle time (about 75 'pops') took about 2 minutes... I think these strobes are from the fifties, very retro. Anyway I was wondering about a few things....

    What is the downside to the strobe method? (besides standing about hitting a thumb switch 75 times) I have about 6 of these heads so I am thinking of rigging up something like a reflective box or closet. I am thinking that there is a possibility for very precise exposure control. Or is this just another wacky idea that any rational person would abandon.

    When I have done sun prints my times for some negatives have been as high as 20 minutes so I am surprised at the times I am getting with the strobe. What are the average exposure times that other Pd printers are experiencing with other light sources?

    Thanks in advance for your patience and informative answers!

  2. #2

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    I'm really interested in your idea for strobe exposure for contact printing. sounds like a great idea. My only thoughts are with the multiple heads you will need to support them above a piece of diffused plastic. Far enough away that the lights overlap each other for even light coverage. As far as how many pops really depends on how many watts your driving through the heads. With 6 heads however it's not going to take much. (I'm guessing) My current setup is a light bank is 6 24 inch 300 watt black lights 4 inches above the contact plate. My exposure times are around 10 minutes.
    Please keep us posted I'm curiousto see how it works out.
    Stop trying to get into my mind, There is nothing there!

  3. #3

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    Bessler/Minolta came out with a color head a number of years ago that used pulsed Xenon as the source of a very precise light source. I would imagine that your idea about strobes would be applicable to your desired application since these are usually pulsed Xenon. Pulsed Xenon does have a UV componant and that is what exposes Pd and other processes too. Some of the more current tubes do have a coating to reduce the emission of UV while permitting the passage of the visible light componant. The age of your strobes may be in your favor for this application.

    If I were going to try what you are wanting to do, I would probably bounce the light source against a reflective surface and then through a diffusion screen much like a softbox but making the light diffuse one extra step rather then just firing it through the diffusion. My reason for this is to gain eveness of light striking the print.

    In my work on an Azo light source, which also works with UV, I have found that there is a material made by Miro called Miro Silver. This is a specially coated aluminum that is 96% reflective insofar as the UV spectrum. Not all materials reflect or transmit UV effectively.

    Good luck...sounds as if you have an interesting project.

  4. #4
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    If you are ever lucky enough to find a pulsed xenon light set off an old copy camera grab it up. It will do exactly what you are going for with the added feature of a continuous on time during exposure. It manages this by not running full power for the tubes rated capacity and pulsing an arc through the tube instead of one big pop.
    The major thing to watch for when using studio strobes for this task is heat dissipation. Push them too hard and you may blow a tube due to overheating. The highest power xenon tubes have a water jacket to keep things cool. If you notice your units suffering try to get some extra cooling with a blower of some type and give it a rest break. The print will wait.

  5. #5

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    "6 24 inch 300 watt black lights "

    Thomas, don't you mean 30 watt black lights? I use 8 18 inch 15 watt black lights in my 8x10 box and the exposures are about 10 min. 1800 watts would do a turkey in 10 min. :-)

  6. #6

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    Sorry for the mis-type, yes 30 watt.
    Stop trying to get into my mind, There is nothing there!

  7. #7

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    Do you have a way of tripping all six lights at the same time? if they all charge from a power pack then I would set up the lights in a ring around the easel and pop them. This will provide you with even ilumination without the need of diffusers or bouncers.

    2 mins is a great time, my standard printing time is about 11 min or 500 units of light with my plate burner.

  8. #8

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    Yes, each head has it's own power pack with adjustable output and they can fire simultaneously. I am still fence sitting on the lighting issue (among others) so with the dozen extra bulbs (rather peculiar looking) I have on hand I could use this as my rainy day method for a while if it works. Thanks again for your patience with yet another of my quirky ideas.

  9. #9

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    Quote Originally Posted by Annie
    Yes, each head has it's own power pack with adjustable output and they can fire simultaneously. I am still fence sitting on the lighting issue (among others) so with the dozen extra bulbs (rather peculiar looking) I have on hand I could use this as my rainy day method for a while if it works. Thanks again for your patience with yet another of my quirky ideas.


    Annie,

    This is an interesting idea but before putting too much time into the project make sure that it is actually more efficient that a bank of UV tubes, such as BL or BLBs. You did not mention the distace oif the strobe from the printing source and this matters a lot because the inverse square rule applies and I suspect that in order to get adequate eveness to expose a 11X14 or larger print, even witih six or eight strobes, you will have to place the lights at from 18-24" from the printing frame. And , if you diffuse the light to get beter eveneness your exposurs will be even slower.

    Another consideration is coinsistency. Many of us are using light integrators to measure the actual amount of light on the print since this can vary with voltage fluctuations and time of operation of the light. Will you be able to get the necessary consistency with a multipl strobe, multiple flash system. I fankly don't have a clue as to the answer but for sure having to trip the flash some 75 times of more to make a print would get in the way of my printmaking.



    Sandy

  10. #10

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    Mar 2003
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    This is just a temporary strategy until I have a better concept of where my photography and printing are headed. At this point I think I am a little more 'freestyle' than most of the printers on this forum. In a few months I will probably get in the plumbers knock out a few walls and assemble a 'proper' darkroom and platinum printing set-up. Mind you I am also considering getting a big ol' wooden sailboat and heading south for a few years, so in that case I will sun print on deck and develop in the world's smallest floating darkroom...

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