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  1. #11

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    Thats easy enough to test, try two bulbs next to each other on your alternative substrate, one pointed down and one sideways. This would also give you a good idea of how much coverage to expect.
    art is about managing compromise

  2. #12
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    I suspect why nobody does the sideways bulb configuration is the amount of real estate you'd lose to the socket configuration. You'd be far more likely to get banding in your prints from the wall you'd have to make to mount the sockets on. The reduced light level from having the bulbs a bit more spread out would be a far easier price to pay (slightly longer exposure times) than having banding in your prints from obstructed lightpaths.

  3. #13
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    Fly -

    That's a valid concern if you design the box so that the sockets are bottom-to-bottom on a strip down the middle. But what about the case where the size of your box requires only two rows of lamps. In that case, you could mount the lamps with their bases on the outside. I would think that would avoid the banding problem.

    The basis for my question about horizontal mounting was the thought that this could be a more efficient arrangement if more light is emitted from the sides of the spiral than from the top. On the other hand, in the horizontal design, only one side actually faces the contact frame. So perhaps the answer comes back to maximizing the UV reflectivity of the inside of the box in order to take advantage of as much as possible of the emitted light. That's why I'm planning to line the inside of the box with sheet metal (actually, aluminum flashing).

  4. #14
    Donald Qualls's Avatar
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    Quote Originally Posted by sanking
    Just curious where you saw spiral BL tubes for sale? So far I have only seen BBB.
    Don't know that I have seen BL spirals, as opposed to BL-B. Straight tubes come in both, but my brain was sufficiently overloaded trying to keep track of prices and such when I was looking at them that I might well have thought I'd seen something I didn't.

    In any case, what I've been thinking about is *2* of the BL-B spirals (about $25 plus shipping for a pair) mounted in a pair of $7 reflector clamp lights, which would be stapled in place on a board or similar mount to give them a fixed location. I think two such lamps would let me get even enough light to print 8x10, and I don't have other equipment to support even that size yet -- a single would probably work for 5x7 and smaller.

    First, however, I plan to try Cyanotype Rex, which I've heard is fast enough to allow in-camera negatives and paper-to-paper contact prints -- which implies it might also be usable for actual enlargements under a cold light head...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  5. #15

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    Just for the record, somebody posted a message ( not sure if on another thread on apug.org. or elsewhere) that the spiral BLB tubes can not be used in horizontal orientation due to the nature of the ballast. I have no idea if this is true, but I know for a fact that it was said, and the poster did seem pretty confident of the information.

    Sandy

    Quote Originally Posted by Monophoto
    Fly -

    That's a valid concern if you design the box so that the sockets are bottom-to-bottom on a strip down the middle. But what about the case where the size of your box requires only two rows of lamps. In that case, you could mount the lamps with their bases on the outside. I would think that would avoid the banding problem.

    The basis for my question about horizontal mounting was the thought that this could be a more efficient arrangement if more light is emitted from the sides of the spiral than from the top. On the other hand, in the horizontal design, only one side actually faces the contact frame. So perhaps the answer comes back to maximizing the UV reflectivity of the inside of the box in order to take advantage of as much as possible of the emitted light. That's why I'm planning to line the inside of the box with sheet metal (actually, aluminum flashing).
    Last edited by sanking; 02-02-2006 at 12:22 AM. Click to view previous post history.

  6. #16

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    Quote Originally Posted by Donald Qualls
    In any case, what I've been thinking about is *2* of the BL-B spirals (about $25 plus shipping for a pair) mounted in a pair of $7 reflector clamp lights, which would be stapled in place on a board or similar mount to give them a fixed location. I think two such lamps would let me get even enough light to print 8x10, and I don't have other equipment to support even that size yet -- a single would probably work for 5x7 and smaller.
    For what it's worth, after a suggestion from Sandy King, I've been using a single spiral BLB (Feit Electric -- I bought mine from topbulb.com) in a reflector clamp light to make my Van Dyke Brown prints (6x9"). It works well -- exposure time is about 8 minutes with my digital negs, at a distance of something like 40-50 cm.

  7. #17

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    Thanks for the report. Sounds like you have found a very inexpensive and efficient exposing system for your UV printing.

    Does not take much to figure that if you ganged up a number of those tubes you could make big prints with a very small investment in the light source.

    Best,

    Sandy


    Quote Originally Posted by Jordan
    For what it's worth, after a suggestion from Sandy King, I've been using a single spiral BLB (Feit Electric -- I bought mine from topbulb.com) in a reflector clamp light to make my Van Dyke Brown prints (6x9"). It works well -- exposure time is about 8 minutes with my digital negs, at a distance of something like 40-50 cm.
    Last edited by sanking; 02-02-2006 at 09:54 AM. Click to view previous post history.

  8. #18
    Monophoto's Avatar
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    Quote Originally Posted by sanking
    Just for the record, somebody posted a message ( not sure if on another thread on apug.org. or elsewhere) that the spiral BLB tubes can not be used in horizontal orientation due to the nature of the ballast. I have no idea if this is true, but I know for a fact that it was said, and the posted seemedm pretty sure of the information.

    Sandy
    0

    Sandy -

    When I first raised the question (another thread, perhaps another board), I mentioned that when CFLs were first introduced, the manufacturer's did impose constraints on mounting - the choices were base up or base down.

    I just did some research in the other thread and found the following note from Nick Zentana:

    "I'm not sure all those issues you mention have been cured. When I was looking at using them for an enlarger head I found a few things.

    1) The bulbs over a certain size don't like being enclosed. Heat becomes a issue. I think 28watts. That's one bulb. If you're using multiple bulbs I bet you need to worry about cooling even if the bulb is rated for enclosed fixtures.

    2) The bigger bulbs can only be burned bulb up."

    Perhaps this is what you were recalling.

    A logical followup question is "what is a bigger bulb?" I've seen some very large CFLs (equivalent to upwards of 300w of incandescent), But I've only seen smaller (eg, 20 and 27 watt) spiral BLBs listed on various web sites - are there any restrictions on these spiral BLB bulbs?
    Last edited by Monophoto; 02-02-2006 at 09:34 AM. Click to view previous post history.

  9. #19

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    Absolutely, Sandy. My next challenge is actually coating the VDB sensitizer evenly on the paper (my coating rod technique needs major work -- I get "stains" or uneven coating). It would have been even better if I could have found the bulb locally, but I couldn't find a Canadian supplier of the spiral BLBs.

  10. #20

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    My advice would be to junk the coating rod and get the Richesoin 9010, called by many the "Magic Brush". It makes coating a snap. The Richeson is not cheap but it is a good investment in your printing technique.

    Sandy




    Quote Originally Posted by Jordan
    Absolutely, Sandy. My next challenge is actually coating the VDB sensitizer evenly on the paper (my coating rod technique needs major work -- I get "stains" or uneven coating). It would have been even better if I could have found the bulb locally, but I couldn't find a Canadian supplier of the spiral BLBs.

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