Halogen bulbs for hand-coated silver emulsion

Discussion in 'Contact Printing' started by HenceForthWith, Jan 16, 2005.

  1. HenceForthWith

    HenceForthWith Member

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    Hi all,

    I've have a nice copy of "Silver Gelatin: A Users Guide to Liquid Photographic Emulsions"--which is a beautiful book--sadly collecting dust on my bookshelf. So, I'm ready to rectify that...

    I have a good supply of halogen (tubular, w/ceramic ends) bulbs, from 300w to 1000w. The type you would use in a Lowell Tota Light. I also have several fixtures with nice reflectors. Can these be used for a light source for contact printing? Maybe two of the lower wattage bulbs in a wood frame of sorts? I'm not going to be using them for any other alt processes.

    I realize they run hot and much care has to be taken to not contaminate the surface of the bulbs. But that aside, will they work?

    I'm only doing up to 8x10, some with in-camera 4x5 negs, the rest will be with enlarged inkjet negs.

    Any suggestions, comments, peals of laughter?

    Thanks,

    Jon
     
  2. Ryuji

    Ryuji Member

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    If you are doing silver-gelatin process, why bother with contact printing? Make an enlarging speed emulsion and you are all set. Don't sell your enlarger and timer just yet! (well, they don't bring you money anyway)

    That book has very good illustrations of how you can use emulsions but I find numerous errors and inappropriate suggestions when it comes to chemistry of emulsion. The formulae contain errors, both in the emulsion section and processing chemistry section. Indeed, the emulsion formulae in that book are pretty obsolete.
    But the book is very good in showing how you can use emulsion creatively, and many of the things said in the earlier half of the book are useful.
     
  3. eric

    eric Member

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    Didn't Weston use a regular 'ol lightbulb for contact printing?
     
  4. HenceForthWith

    HenceForthWith Member

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    Hi Ryuji,

    Ah... guess I forgot some info. I don't have an enlarger. My bathroom here in Brooklyn is tiny and while an enlarger is in the greater plan, it ain't happening yet.

    I don't plan on making my own emulsion--I'll be using something off the shelf (suggestions?), so the section on chemistry isn't very important to me. I mostly bought the book for inspiration.

    Also, at some point in the future, I plan on doing other alt processes and I think this will be a good primer.

    How about them halogen lights? :D
     
  5. HenceForthWith

    HenceForthWith Member

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    I read that somewhere. I'm asking because:

    1. These might print faster than a regular 'ol lightbulb
    2. I like making things
    3. I already own the damn things... :D

    Jon
     
  6. smieglitz

    smieglitz Subscriber

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    Jon,

    I've used a 1000w quartz FEL lamp out of a Lowell studio light (DP?) with great success when printing gum bichromate. I actually get much better results with this lamp than other sources most printers recommend (I.e., UV fluorescent tubes which cause fog IME).

    However, I think such a lamp may be overkill with a silver emulsion unless it was extremely slow like salted paper. And, heat is also a problem as you indicate. For a standard liquid silver emulsion I think you might be better off with a household incandescant bulb around the 60w range. I think you will have much greater control with a weaker lamp and a relatively fast emulsion.

    Joe
     
  7. HenceForthWith

    HenceForthWith Member

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    Hi Joe,

    Ah--that was what I was looking for. Having more control with lower wattage makes lots of sense. Hmmm, I've thought of using some form of diffusion with the lower wattage lamps, which might lower/spread some of the light. Might still be waaaay too much for that emulsion. I'll try and rig up something and give it a go.

    I wonder if there is any benefit to using, say, a grow lamp for this? I guess the question is 'what is the best light source for hand-coated emulsion'?

    Thank you,

    Jon
     
  8. Ole

    Ole Moderator Staff Member Moderator

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    Don't know about that, but I use a grow lamp for alternative processes - cyanotypes, van dykes, salt print etcetera. No reason it shouldn't worl with gelatine/chloride, albumen and the like.

    Hmmm... I've got to try that! Usable sunlight is still a couple of months off here...
     
  9. Ryuji

    Ryuji Member

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    I see. Enlarging emulsions are pretty fast, so you want to use a dimmest possible light, and quite a bit of distance above the contact printing frame. My very first print was made by contact printing on Ilfospeed grade 3 in my bedroom in college dorm bedroom. I had to use 3 pieces of 3x5 cards stacked to cover the 50W halogen desk lamp. Yet the exposure times was a single digit seconds, as I recall.
     
  10. HenceForthWith

    HenceForthWith Member

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    Hi,

    I mean off the shelf emulsion like Liquid Light. Seems like a frosted bulb (or one of the halogens with opal glass or the like) would do just fine.

    Jon