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  1. #1

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    Long printing times - when they're really long? :)

    Hello friends,

    after switching to FUJI color enlarger with diffusion head, my exposure times became quite long on my opinion - sometimes a minute, sometimes two and three, depending on neg density, lens aperture and magnification. The question is, are these times not too unusually long? I can't see any image degradation on my prints, but still I'm not used to dim enlargers I see that in my enlarger the illumination is sacrificed in favour of field evenness, but still it's a bit worrying

    BTW, Fujinon EXs are truly amazing - both 50 and 105 give the same sharpness wide open and stopped, believe it or not! How could it be?

    Cheers, Zhenya

  2. #2
    Ian Grant's Avatar
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    Times do seem to be long. Have to assume your making medium size enlargements.

    The first question is has the enlarger got the correct wattage halogen lamp(s), as this would make a very significant differance.

    The second is the density of your negatives, this can also cause long exposure times.

    Typically with a colour head printing on B&W paper I would expect exposures in the range of 15 - 30 seconds printing approx 20 x30 cms and sopping the lenses down to f11 -f16.

    Remember that the speed od B7W paper vaies significantly between manufacturers, and this alone can make a differance of 2 stops

    Ian

  3. #3
    RH Designs's Avatar
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    I don't think it's that unusual with colour enlargers. My exposure times are often around a minute for a 16x12 (using an LPL C7700), and if you're using warmtone papers, the slower speed will increase exposure time. On the upside, a long exposure makes it easier to dodge areas.

    I've found my Nikon lenses just as good wide open as two stops down. Somebody once told me that enlarging lenses are actually optimised for wide open, but I don't know if that's true in general.
    Regards,
    Richard.

    RH Designs - My Photography

  4. #4

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    Ian,

    the wattage is a bit less than required - 100W instead of 150W, I had to make this change because 100V 150W original Japanese lamps are not available anymore. But the very construction of the mixing head makes it VERY even yet dim - you see, the light enters it from the side, and there's three center filters (!) inside to ensure the illumination uniformity. I've printed an empty frame on a ultrahard paper - the graying was perfectly even, so the light mixing box works miracles

    So maybe it's easier just to get accustomed to my enlarger, eh?

    Cheers, Zhenya

    Quote Originally Posted by Ian Grant
    Times do seem to be long. Have to assume your making medium size enlargements.

    The first question is has the enlarger got the correct wattage halogen lamp(s), as this would make a very significant differance.

  5. #5

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    Yes, the light mixing box eats away plenty of light - but in return making the illumination very good and even. So unless it causes real troubles, the long exposure times are not the subject of serious worrying, right?

    Cheers, Zhenya

    Quote Originally Posted by RH Designs
    I don't think it's that unusual with colour enlargers. My exposure times are often around a minute for a 16x12 (using an LPL C7700), and if you're using warmtone papers, the slower speed will increase exposure time. On the upside, a long exposure makes it easier to dodge areas.

    I've found my Nikon lenses just as good wide open as two stops down. Somebody once told me that enlarging lenses are actually optimised for wide open, but I don't know if that's true in general.

  6. #6
    Ian Grant's Avatar
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    Zhenya

    I found an excellent source for halogen bulbs for my Devere enlarger, it uses 4 120v 300w.

    Will have a look for ther website, I think the bulb your after should be available.. Using the correct wattage bulb will make a very big differance, and give you more flexibility.

    Ian

  7. #7
    Ian Grant's Avatar
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  8. #8

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    Ian,

    the correct wattage bulbs would require plenty of things from me - for example, a correct transformer capable of giving at least 30A 12V. The 12V(15V) 150W bulbs are quite expensive, and their lifespan is around 30h, while my 220V 100W 1500h household bulbs cost less than a dollar, and available everywhere. More, the colour head has two identical bulbs - one for printing, one for focusing, and when they are switched on together (that's 200W instead of 150W), the difference in exposure times is not at all very dramatic So it's the enlarger that is built to be dim, and 150W wouldn't give any BIG difference. But I just love the prints it gives, and the ease of work with it

    Cheers, Zhenya

    Quote Originally Posted by Ian Grant
    Zhenya
    Will have a look for ther website, I think the bulb your after should be available.. Using the correct wattage bulb will make a very big differance, and give you more flexibility.

    Ian

  9. #9
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    Richard is correct. Enlarging lenses are fairly good wide-open. The typical recommendation of stopping down at least two or three stops was put in question by Ctein in his book 'Post Exposure', who published the max quality aperture for many enlarging lenses. Many of them performed better wide-open. I have gone to stopping down for just one stop, max two if times are too short for dodging and burning.

    Just make sure your safelights are 'safe'. Long exposure times give the gremlins in bad safelights a chance to jump all over your print.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  10. #10

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    Quote Originally Posted by eumenius
    I and their lifespan is around 30h, while my 220V 100W 1500h household bulbs cost less than a dollar,

    The lifespan for enlarger bulbs is because of how they are used. For example my enlarger bulbs are rated at 50 hours but the same bulb used in some other devices is rated at something like 1000 hours. Why? I think the main reason is the constant on/off cycling that enlarger bulbs get. If you treat your household bulbs like enlarger bulbs don't be surprised if they don't outlast the enlarger bulbs.

    To the intial question. Are you getting the same long times with both formats? Are you using a smaller lightbox for 35mm? Is the lightbox dirty inside?

    I've no problem with times on my Beseler colour head. OTOH my Durst is slower. Both use the same bulbs.

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