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  1. #21

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    Miles,

    There is no "ideal" printing time, though intensity of light and length of exposure can affect contrast, though for that to happen times need to be at the extremes.

    If you are printing pt./pd. with in-camera negatives you should expect exposure times to be in the 5-10 minute range with the 1000 watt setting. HID metalhalide lamps do not reach full radiation until a minute or more after you turn them on so light integrators are used to time exposure in units, and the unit can be calibrated to whatever amount of time you like. I am sure your unit has a built-in integrator so this should not be an issue.

    Sandy

    Quote Originally Posted by MVNelson View Post
    Sandy, perhaps one day when I'm feeling ....fast...I wil throw on a welder's helmet and leaded gloves and push THAT button. For now I will be satisfied with using what the manual calls "low intensity setting" 1000Watts. Is there an "ideal" printing time with alt. printing? Is the quicker the better or should you spread the time out longer for ,say, dodging and burning? I will calibrate this pm and I need to target a "reasonable" exposure time (maybe...5 minutes?). Suggestions? I'm so anxious to see a pt/pl print that I thought....Just go out there and slap some coating on that paper ,dry it,stick any negative on that paper and slide into that vacuum frame, close and shield eyes, push the manual button and count to 180, retrieve the paper and process, all the time hoping for the best! At this point after all the delays I just want to Git-R-done.....

    Hopefully something tonight !

    Miles

    p.s. I aint a feared of that there 6000W button I just can't figure out how I'll ever learn Carbon printing reading Braille....

  2. #22

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    I have the AmerGraph ULF-28, which uses a 1200 watt continous wave xenon light source. When prnting well-exposed negateives y exposure times for palladium are less than two minutes. Course, it is hard to equate times because speed of printing varies a lot with conditions of RH, but the ULF-28 is a lot faster than my bank of BL tubes, and the BL tubes print faster than the NuArc 26-1k I previously owned.

    One of the real attractions of the CWX light is that radiation reachs full output within just a few seconds of firing up the unit. Another is that you can re-strike almost immeidately after turning it off. If anyone is actively looking for a new UV light source I highly recommend the ULF-28, which is in my estimation the "Ferrari" of UV light sources in the 1000-1500 watt range. See my review of the ULF-28 at the unblinkingeye web site.

    Sandy




    Quote Originally Posted by wilsonneal View Post
    MV Nelson wrote: I will calibrate this pm and I need to target a "reasonable" exposure time (maybe...5 minutes?). Suggestions?

    I have an Amergraph platemaker with a 1200 watt Mercury lamp. Most of my exposures are running about 6 minutes for PtPd. My exposure unit has a built-in integrator that keeps track of fluctuations in light output, so I don't set 'minutes' as my target but 'units' of light. I would expect yours also has an integrator. Play with the integrator/timer (without negs or sensitized paper) until you determine how many units gives you about 5 minutes? That's how I began my calibration process, and arrived at a standard of about 30 units for most negs.
    N

  3. #23
    MVNelson's Avatar
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    Sandy,Wilsonneal and FlyingCamera(is there a story behind the name?) I really appreciate your help and suggestions for calibration. I know that it is hard to be precise in this situation but starting points are very helpful. We (i'm doing a tom sawyer act as we speak) are Hanging, framing and bolting the light source as i write. They...I mean we are having a little snag getting the thing centered up. The original framing was not sent with the units and they...I mean we are having to custom built it. Yet another delay but it gives me a chance to find out why I have ammonium citrate instead of potassium oxalate as my paper developer(it came with the kit). I notice most postings and seem to be mostly using pot. ox. ??? I have a lot to learn. I better run they...I mean we are at a decision point .

  4. #24
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    the next time you order a kit, or just want to replace your developer, call Bostick & Sullivan and ask them to swap out the Ammonium Citrate for a bottle of PotOx. Ammonium Citrate works as a developer - I think it is also cheaper, so that's why they put it in the kit.

    The story behind the name, The Flying Camera, is that it is the name of my business - I started out trying to offer adventure tours to interesting places for photographers. It's been on hold for a while.

    Whatever your tool for exposing your prints, you'll have a blast at it. The learning curve isn't nearly as steep as you're afraid it will be, especially with all the really kind folks here on APUG to help you out.

  5. #25
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    Thanks for the encouragement TFC(sorry for the abrev.), I have noticed that there is a wealth of wisdom here and delivered with much needed humor, espacially during my time of trial and tribulation with getting this light source up to snuff. They...I really mean we seriously decided to knock off till tomorrow. Only thing left to do is hang the curtains...the holding rings were too small. I wouldn't use the unit without the cutains...Hmm does flying imply like your are a pilot and flew folks to photo destinations? I call B-S and told them to send some Pot Ox. I also noticed they had a sale on Pd sol.#3 I wonder is this a real deal or just a bit of hype ? Your suppose to save $52.00.

    Miles ,nuff for today!

  6. #26
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    Oh, the discount is the real deal. jump on it before they change their minds. No, I'm not a pilot. More like glorified tourguide packing large format gear. The genesis for the idea was a trip I took to Cambodia to photograph Angkor Wat, and it was just me and my guide. I had the freedom to photograph what I wanted, on pretty much my own schedule.

  7. #27
    bill schwab's Avatar
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    Quote Originally Posted by TheFlyingCamera View Post
    Ammonium Citrate works as a developer - I think it is also cheaper, so that's why they put it in the kit.
    I think the biggest reason is that it is less toxic and safer to use for the beginner. Pot Ox should be handled carefully.

    Bill

  8. #28
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    I like the idea for less toxicity...because of my line of work which has it's signifigant inherent risk factors "safe and sane " use rings loud and clear..

    Miles

  9. #29
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    PotOx comes from Rhubarb. Yes, you need to be careful with it, but the biggest hazard from it is easy to avoid - just don't get your hands in it and don't drink it. Reasonable safety precautions are all that is needed. If you're worried about absorption, a set of inexpensive nitrile gloves from the drugstore will do the trick. If you have small children around the house who are prone to getting into your darkroom and messing around, stick with the Ammonium citrate. Then again, if you have small children who are prone to messing around in your darkroom, don't hook up that 6000 watt exposure unit.

  10. #30
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    I practically live in gloves all day. Yeah, my darkroom is secure from intrusion . The unit is out in another room and it too is secure (from the big kids that run around here from time to time).

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