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Thread: AZO Lightsource

  1. #11
    bmac's Avatar
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    What SPF would you have to wear while working with a 1000w HID bulb?
    hi!

  2. #12

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    I've been using a R40 65w floodlight/bulb in a reflector from Home Depot. I hang it 3 feet above the contact print frame and the times are around 9 - 13 seconds. The bulb cost around $5. I only started printing with Azo this year so maybe I'm missing something but why would you buy a special bulb?

  3. #13

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    Quote Originally Posted by bmac
    What SPF would you have to wear while working with a 1000w HID bulb?

    I wouldn't worry about that. Just change my race to african american.

  4. #14

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    Quote Originally Posted by mwtroxell
    I've been using a R40 65w floodlight/bulb in a reflector from Home Depot. I hang it 3 feet above the contact print frame and the times are around 9 - 13 seconds. The bulb cost around $5. I only started printing with Azo this year so maybe I'm missing something but why would you buy a special bulb?

    My experience seems consistant with most others in that when the density range of the negative is consistant with the exposure scale of Azo paper that the negative exhibits enough density to require fairly lengthy exposure times.

  5. #15
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    I am beginning to think that the source of my exposure issues is not with my light, but with the glass in my home made print frame. It is 1/4" thick, maybe it is the type that blocks UV... I'll try it with another piece of glass tomorrow.

    Brian
    hi!

  6. #16
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    Quote Originally Posted by bmac
    What SPF would you have to wear while working with a 1000w HID bulb?
    At work the platemaking units that used UV light sources had curtains to block exposure to the operator. It's also recommended to use yellow UV blocking glasses when working with such bright UV sources, see the dentists office when they UV cure that polymer filling. UV gun has an orange filter ring around it and the operator wears the glasses.
    Upshot is if you build a high output UV light source for your alternative processes you really do need to take steps to protect yourself, especially your eyes, from the higher energy light.
    Gary Beasley

  7. #17
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    Brian, 1/4" sounds a bit on the thick side. If it is normal float glass, it will reduce the U.V. light quite a bit. Just as an experiment, try using the thinnest glass you can find that is available (single strength window pane), even if it does not give the compression of thicker glass. This may affect print quality adversely, but it will tell you if there is a problem immediately from glass thickness.

    What size prints are you making? A sheet from a regular picture frame that is the correct size will work. You could also try leaving one edge of the print and negative exposed to light without the glass, to see about times and exposures as a comparison test.

  8. #18

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    I use a vacuum frame but in the past used 1/4" plate glass with no problem. Yes the 300W lamps are expensive. I use the 45watt reflector lamps at about 12 seconds for most proofs from pyrocat negatives. Some of my ABC negatives, that are technically overdeveloped, require the 300w lamp. For other printing I have a 1000 watt HID installed, you certainly won't need that for AZO.

  9. #19
    bmac's Avatar
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    Quote Originally Posted by noseoil
    Brian, 1/4" sounds a bit on the thick side. If it is normal float glass, it will reduce the U.V. light quite a bit. Just as an experiment, try using the thinnest glass you can find that is available (single strength window pane), even if it does not give the compression of thicker glass. This may affect print quality adversely, but it will tell you if there is a problem immediately from glass thickness.

    What size prints are you making? A sheet from a regular picture frame that is the correct size will work. You could also try leaving one edge of the print and negative exposed to light without the glass, to see about times and exposures as a comparison test.
    I'll try the regular picture frame glass. I am doing 8x10's with a 65w grow light about 2' above the print frame. 145 second exposures right now. Something is up...
    hi!

  10. #20

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    Quote Originally Posted by bmac
    I'll try the regular picture frame glass. I am doing 8x10's with a 65w grow light about 2' above the print frame. 145 second exposures right now. Something is up...
    What is the peak density on your negatives? What is your density range on the negative? If the negatives are overexposed and then developed to the proper density range the printing exposure times will be lengthened.

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