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  1. #21
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    In October APUG member "Peters" was selling an 11x14 Edwards. I chose to buy a new one partly because of the trade up policy and a possible interest in a banquet camera down the road. If Peters' unit is still available it gives you another option.

    John Powers

  2. #22

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    I appreciate everyones participation. I have purchased the Nuarc exposure unit that comes together with vaccum frame and now await delivery.
    I am very eager to print many of my AZO negatives. What process? Kallitype first to learn the coating and the tuning up of the system. Carbon? Sure that too. Platinum, you may ask? definetly. Sooner or later I may incline over on process or another. Maybe not, maybe I will print the negative with the process I feel gets the most of it.
    Will see, for now I have a great learning curve to climb.

  3. #23
    edz
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    For alt process, if I'm not mistaken one wants 312nm tubes and these, I think, beyond cost also demand some form of UV safety shield--- typically plexiglass. The models I've seen for the spectral sensitivity of these materials indicates that the popular "home brew" black-light lamps are a waste of energy as their UV cutoff is quite high at all wavelenghs were the materials are not as sensitive as with shorter wavelength.. This is why I've suggested we might want to look at the UV transilluminators used for gels.. seems to have similar wants..
    Edward C. Zimmermann
    BSn R&D // http://www.nonmonotonic.net

  4. #24

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    Quote Originally Posted by edz
    For alt process, if I'm not mistaken one wants 312nm tubes and these, I think, beyond cost also demand some form of UV safety shield--- typically plexiglass. The models I've seen for the spectral sensitivity of these materials indicates that the popular "home brew" black-light lamps are a waste of energy as their UV cutoff is quite high at all wavelenghs were the materials are not as sensitive as with shorter wavelength.. This is why I've suggested we might want to look at the UV transilluminators used for gels.. seems to have similar wants..
    I am not sure where you got the idea that one needs tubes of 312 nm for alternative processes but it is incorrect in my opinion. I have actually tested processes such as carbon, gum, kallitype and Pt/Pd. with reptile type tubes that emit radiation in this range and they were actually less efficient than tubes that emit in the 350nm to 420nm range. With most processes the loss of efficiency is due to the fact that plain float glass absorbs virtually all radiation in the 312nm range so it is useless to the process. Even specialty glasses designed for maximum UV transmittance absorb most of the radiation in this range so for all practical purposes, assuming we use glass in our contact printing frames and vacuum easels radiation at 312nm is useless to alternative processes. It is also very dangerous, but since it first and foremost useless to our processes there is no point in belaboring this fact.

    Sandy

  5. #25

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    I have been using an Olec Al 15 unit for exposure; my standard platinum printing time with dense pyro developed negatives is 3-4 mins using the Olec 1261 bulb. This exposure is much faster than my Black Light bulb unit. The Al 15 is no longer made and the original bulbs no longer supplied by Olec, but third party suppliers have the original bulbs. The Al 15 can also have the capacitors re-wired (4 capacitor model) to accept the new bulbs. The 1261 is called a photopolymer/diazo bulb, when you examine its spectrum (see Olec website) is has an output across the spectrum from 320nm through the visible range, unlike the 1251 which has a variable output. You can find used Olec and Theimer Violux units on ebay, and elsewhere on the net. You can find support for these units from Olec, Douthitt Corp (very helpful) and LexUSA. With the correct bulb these I believe represent the fastest exposure options. These units can be used with or without vacuum frames, so they are adequate for POP and DOP processes.

  6. #26

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    I have just received my 26-1k exposure unit and it is right now burning on my studio floor for a check up. I put the unit to burn 500 units. I noticed that it cycles on and off every some 150 units, maybe to regulate the working temperature. Is this normal?
    Also, when I turn on the unit the fan seems to blow bull blast, yet when the lamo goes on the fan reverses the rotation and it now does it much slower. Is this also normal?

    Thanks for your help. I could not find an operation manual at the nuarc website.

  7. #27

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    Quote Originally Posted by Christian Olivet
    I have just received my 26-1k exposure unit and it is right now burning on my studio floor for a check up. I put the unit to burn 500 units. I noticed that it cycles on and off every some 150 units, maybe to regulate the working temperature. Is this normal?
    Also, when I turn on the unit the fan seems to blow bull blast, yet when the lamo goes on the fan reverses the rotation and it now does it much slower. Is this also normal?

    Thanks for your help. I could not find an operation manual at the nuarc website.
    None of what you describe is normal operation for my 26-1k unit, or for any 26-1k or 26-1ks units that I have worked with.

    With my unit the bulb comes on and gradually reaches full output in about a minute or so, and the fan has constant output in only one rotation.

    Sandy
    Last edited by sanking; 12-27-2004 at 10:30 PM. Click to view previous post history.

  8. #28

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    Quote Originally Posted by sanking
    None of what you describe is normal operation for my 26-1k unit or for any 26-1k units that I have worked with.

    With my unit the bulb comes on and gradually reaches full output in about a minute or so, and the fan has constant output in only one rotation.

    Sandy
    Thanks Sandy! Jorge had mentioned that my unit is a fairly new model. I wonder if in this model they had the cooling system updated. I will check tomorrow with Nuarc.
    I don't like the idea of waiting forever to make a print, something has to be wrong.

  9. #29

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    Quote Originally Posted by Christian Olivet
    I have just received my 26-1k exposure unit and it is right now burning on my studio floor for a check up. I put the unit to burn 500 units. I noticed that it cycles on and off every some 150 units, maybe to regulate the working temperature. Is this normal?
    Also, when I turn on the unit the fan seems to blow bull blast, yet when the lamo goes on the fan reverses the rotation and it now does it much slower. Is this also normal?

    Thanks for your help. I could not find an operation manual at the nuarc website.
    The fan system might be updated, but the cycling every 150 units is definitly not right, or at least it is a setting that does not make sense. The guys at NuArc are pretty good, give them a call and ask them about this cycling.

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