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  1. #1

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    Lamp WAY too bright - Prints too dark

    Having bought the Fujimoto 450 M enlarger (see this Forum), it is beautiful. But I'm having a problem. My exposures in printing are far too short. I am stopped down on the enlarging lens to f.11. I am using a enlarging lens 80 mm lens. I am using Agfa Multicontrast paper. My developer is Dektol 1:2. Yet still, I cannot expose for more than 5 seconds (f.11) without having a black print (extreme overexposure in the enlarging). I have not replaced the lamp that comes with the enlarger or tinkered with it in any other way.

    This is a dichroic, dedicated VD enlarger.

    http://www.jobo-usa.com/products/fuji450mm.htm

    The light source is a 250W Halogen bulb.

    Any ideas or suggestions?

    But wait...I come back to edit this post....I've fiirgured this out!! Wrong diffusion chamber! The enlarger came with the 4x5 chamber and the salesperson told me that's all I needed, but he was wrong....there IS a medium format chamber as an accessory.
    Last edited by Gary Grenell; 12-11-2004 at 10:01 AM. Click to view previous post history.

  2. #2
    clogz's Avatar
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    Had the same problem: the lamp (halogen) started burning brighter and brighter and then gave up the ghost.
    Digital is best taken with a grain of silver.

  3. #3

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    Quote Originally Posted by Gary Grenell
    Having bought the Fujimoto 450 M enlarger (see this Forum), it is beautiful. But I'm having a problem. My exposures in printing are far too short. I am stopped down on the enlarging lens to f.11....

    But wait...I come back to edit this post....I've fiirgured this out!! Wrong diffusion chamber! The enlarger came with the 4x5 chamber and the salesperson told me that's all I needed, but he was wrong....there IS a medium format chamber as an accessory.
    Not sure if you are totally set now. If not, have a look at the following dimmer:

    http://www.aristogrid.com/prod02CA_750.htm

    Best $100 I ever spent. Once you've had this, you may never go back...

    JC

  4. #4

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    Changing the mixing box usually makes things even brighter!! I'd say stick with the 4x5 version and forget it.

    As far as I knew, the mixing boxes function was to focus the total amount of light into the area required by the negative. If you move to the smaller mixing box, you'll take the light over the larger area and intensify it further.

    My suggestion would be to stop the lens down further... Try 22 (if you have it).

    What about throwing in some neutral density (filter?) into the mix to cut the light down?

    joe

  5. #5

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    Yes...you're correct...I now realize that the other mixing box (smaller would intensify the light even more). In stopping the lens down further (all the way down) to f.22 I am afraid I would be out of the "sweet spot" of the lens. The idea of the neutral density filter worries me. Where does it go? Is there already not a neutral density filter in the mixing chamber that works as I go from VC grade to VC grade?
    What about a longer enlarging lens? What about going from an 80mm lens to a 120mm lens? That would force me to raise the column of the enlarger and have the light source further away thereby increasing the time. But what about my basic premise that a 5 second exposure is too short? Does anyone disagree with that? Perhaps I should just live with that 5 second exposure? Thanks...Gary

  6. #6

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    I looked at that Website. It says that it is for Cold Light heads and I have a dichroic head. It also says that it is for 750 watt inductive power. Mine is 120 V A.C. With a 240 Watt Halogen lamp. Is that compatible?

  7. #7
    David A. Goldfarb's Avatar
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    If you put a ND filter in the light path above the diffuser it won't have any negative impact on image quality, and you can use lighting gels, which aren't too costly. You could also put a normal optical quality ND filter on the enlarging lens, if that's more convenient.

    Some enlargers give you the option of using a more or less powerful bulb. Can yours do that?

    As far as the exposure question goes--if you want to burn and dodge, 5 sec. is too short. If you want to produce a large volume of prints quickly with no manipulation, then 5 sec. is great. My impression is that Fujimoto enlargers are aimed more at labs that are interested in volume, so it might be that they just have a powerful light source for that reason.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  8. #8
    Bob F.'s Avatar
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    Unfortunately, dimming a halogen lamp will drastically reduce its life - it really needs to run at full temperature to work correctly.

    Are you dialling in the grades on the colour head or using separate filters? If you are dialling in the grades, are you using an equal exposure time system where you use both Yellow and Magenta settings for each grade - this introduces a useful degree of ND.

    Alternately, if you are using separate filters, dialing in the same amount of Yellow and Magenta should act as a ND filter. Cyan has little or no effect as it subtracts Red and B&W paper is, of course, not sensitive to red in the first place...

    I suspect a ND filter beneath the lens is the simplest way to go as you can simply remove it when making larger prints.


    Good luck, Bob.

  9. #9

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    I think that the ND filter in the lens probably makes the most sense. I will speak to JOBO on Monday...thanx.

  10. #10

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    Slower paper? How are your negatives? Using the right light box you'd gain something like 1 stop in light. I'm a little suprised that your times are that fast with just 250watts.

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