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  1. #41
    Curt's Avatar
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    My Beseler 45 bellows assembly arrived today and I am already looking at it for any modifications. I don't think I can do the modification that Danny did with his 23 but I will look at it first to see if it is possible. Then I will look at an above the top bellows unit, where the stainless steel slides are, and make an assembly with film holder lamp holder etc..

    On another note, I am looking at my Beseler Universal head that is missing a controller unit to make it work. This unit has a single bulb, 83 volt, and the three knobs in front to adjust the light temp. If a person had this head and no controller I believe that the bulb could be run from the power supply, the 83 volt transformer inside, with a relay to a timer. The circuit boards would not be used and the knobs could be calibrated. I have a color analyzer to do it. The knobs could be marked for the VC grade positions 1 to 5.

    My other dead head Beseler is the head that has three light bulbs, 83 volt, that are dimmed individually to create the correct color. Each bulb would have to be dimmed and the three together on one relay.

    Curt

  2. #42
    Curt's Avatar
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    This is the head complete with bellows and all hardware. The top bellows would have to go and the negative stage cut out similar to the 23c modification. It's nearly 7 inches across, I would need to get, make or otherwise use a 5x7 negative carrier to see if the opening would be large enough. I believe it just might be. It would save on having to make a box to hold the carrier and use the existing equipment. Might be pretty slick if it works out. LED's anyone?
    Attached Thumbnails Attached Thumbnails 45257.jpg  

  3. #43

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    Update

    I recently changed from Kentmere paper on this enlarger to Oriental. I didn't realize it but the contrast range IS limited with VC paper and these LED lights. The lower grades, -1, 00 aren't a problem. However, the harder paper grades - about 4 and up - have to have a ultraviolet component in the light to work. No UV, no hard contrast grade. Ctein in his book Post Exposure has some interesting info on this.

    The Kentmere VC paper I was using seems to have a really high inherent contrast. When I did my initial tests I didn't have a problem getting a hard contrast with it on my white LED light. Most of the time I had to use a #1 or #0 filter to bring the contrast down to a normal range of tones. Yet when I changed my paper to Oriental VC, I found I couldn't get above roughly grade 3 1/2. Same with Ilford MG, etc. The LEDs I used in my enlarger don't put out any UV, so I can't get the really hard paper grades.

    To anyone building a LED lightsource with white, green or blue LEDs, please be aware of this shortcoming.

  4. #44

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    Danny -

    You are correct about the Kentmere paper - I just started using it and found it to be about 1.5 grades contrastier than normal VC papers.

    Interesting about the LED light at higher grades.

  5. #45
    Lee L's Avatar
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    For those who wish to experiment: There are discrete component LEDs in the UV and deeper blue range 400-420nm, as opposed to the more standard blue LEDs in the 470nm range. That might boost contrast for someone building their own source or willing to replace LEDs in a stock LED light bar.

    Lee

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