Print times for Beseler Dichro 45s?

Discussion in 'Darkroom Equipment' started by vegardjde, Oct 3, 2011.

  1. vegardjde

    vegardjde Member

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    I just got my first enlarger. A Beseler Dichro 45s. It has a 4x5 mixing chamber. I'm printing 5x7 from Tri-x negs developed in xtol. The negs are good but print times are around 90 secs. This seems excessively long to me. I only used one other enlarger and the prints time were around 15 seconds. I don't have an instruction manual so not sure what setting I should use and what times to expect. Any help is appreciated.
     
  2. ann

    ann Subscriber

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    THE times seem a bit long, but it has been my experience with a lot of diffusion enlargers including yours that the times are much longer than a condensor head.

    If the print is acceptable, i tell my students don't worry about the time
     
  3. Bob-D659

    Bob-D659 Member

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    That is very long, depending on what aperture you have the lens set at. I've got the opposite problem, with a 35mm mixing box onto a 5x7, times were around 5 sec at f11. I put in the 4x5 mixer box and now have workable 15 sec times.

    You may have an old bulb that is turning black, or a much lower wattage bulb than normal. My 4x5 durst runs a 250 watt bulb normally. Are all your filters set at zero, and waht aperture setting are you using?
     
  4. ic-racer

    ic-racer Member

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    The quickest printing times will be obtained when the mixing chamber matches the film format size, the bulb wattage is the maximum recommended, and the Magenta and Yellow controls are all on "0" and the lens is wide open. Most people will stop the lens down 2 to 4 stops and not worry about the resulting time.

    Things that affect printing time:
    Paper brand
    Lens F-stop
    Mixing chamber size
    Light wattage
    Enlargement size
    Filtration M and Y

    Things that do NOT affect printing time:
    Cyan filtration
    Lens focal length
    Dust specs on lens and filters
     
  5. vegardjde

    vegardjde Member

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    I've been using a 90mm lens at f11 with yellow around 10-25 and magenta around 70 with cyan at 0. Maybe I'll reset everything to zero and see how it works. I'm using Ilford multigrade fiber. I believe the bulb is 250 watt, at least from what I've read online.

    My pops told me to focus wide open and then to close down two stops for printing. Is his advice correct? What is the difference between printing wide open at 5.6 and closing down to f11.

    I'm not the most patient person in the world so 90 to 120 secs per print for 5x7 makes the process a bit tedious.

    thanks for the help.
     
  6. ic-racer

    ic-racer Member

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    They make it f5.6 so that it is easier to focus, but otherwise you'd use it around f11 when printing. Sharpness tends to start falling off as soon as you close down, but there are significant gains in edge resolution, evenness of illumination and contrast.

    The combinations of Yellow and Magenta add neutral density so each combination prints the same exposure, however, the printing times should not be much different from those required for the separate Ilford filters.
     
  7. MattKing

    MattKing Subscriber

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    Check that the bulb installed is the correct one, and that it doesn't show any damage.

    Caution - these bulbs are fragile, and if you get fingerprints or other moisture or grease on them, you will shorten their life.
     
  8. vegardjde

    vegardjde Member

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    A few more things.

    I'm printing 35mm negs (in this instance). The mixing chamber is 4x5. Lens is 5.6, stopped down to f11. Print size is 5x7.

    Negs are in good shape. Not overexposed or overdeveloped. Have good contrast.
     
  9. Ian C

    Ian C Member

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    To make a 5” x 7” print from a 35mm negative likely requires a 5.5” wide projection for a magnification of 5.87X.

    With a 90 mm lens you’d need about 540mm from negative to print.

    A 50 mm lens requires 402mm.

    The light loss in stops due to using the 90mm lens rather than a 50mm lens is 0.85 stops due to the longer projection distance from the illuminated negative to the print.

    Using an overly large mixing chamber can also increase printing time.

    The combination of the overly long lens and too large mixing chamber are likely the causes of your problem.

    There’s probably nothing wrong with the enlarger, its light source, or lamp.
     
  10. vegardjde

    vegardjde Member

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    Thanks everyone for helping me out.

    I got all excited about getting another mixing chamber for 35mm and MF. Went online, found a used one at b&h for $125. Perfect. Turns out it is for a condenser, not diffuser. I called Besseler and was told that the 4x5 is the only chamber they make for the Dichro 45s.

    Bummer.

    Looks like I'm going to have some long printing times for a while.

    I talked to my pops -- he is my available expert with 40 years of experience -- and mentioned about maybe using a 50mm lens. He said he has never used one and that some people have problems with foreshortening.

    Should I stick with the 90 or get a 50 and see how it goes. I'd prefer shorter print times. I'm just a relative novice at the darkroom printing part of this. If I'm lucky, I need three test strips to get in the ballpark and then maybe two or three print tries. That works out to about 20 to 30 minutes to get a decent print.
     
  11. mikebarger

    mikebarger Subscriber

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    Well, I just went down and cut open the box on a brand new one to make sure it is what I was told it was. It is a 35mm mixing chamber. The guy I bought my enlarger had the 4x5 in the head, a 6x7 in a baggie, and a brand new unopened 35mm chamber.

    I never print 35mm on this enlarger, so I hadn't actually cut the tape on the box to check it out.

    Maybe they don't make these anymore?

    Mike
     
  12. anikin

    anikin Subscriber

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    See if your enlarger has high/low setting. My Omega D5 has one and I always print on High. Somehow I don't think your time is right. Just yesterday I printed a 11x14 print cropped from 6x4.5 negative using 85mm Nikkor. That's little over 6x enlargement just like you did, and my time was about 16 sec at f16 (or f11? I don't have notes with me).
    Anyway, check the lamp - maybe the bulb is for the wrong voltage; check voltage stabilizer - does it provide the correct voltage; filters - are they dirty or stuck in the wrong position; lens - does diaphragm move; mixing chamber - is the white liner missing or heat resistant glass filter dirty? Oh, and check the paper and developer - maybe expired or wrong dilution? I know, silly questions, but that's what I would try to check and not necessarily in that order.
     
  13. natek83

    natek83 Member

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    90 sec is not bad!! I have a really difficult negative and it has a base exposure of 2min 40sec and then I have to burn the sky in for 13min moving a card up and down to smooth the horizon. It makes your arms very tired =( It's 35mm negative on tmax 400 with box development in d76 1:1. I'm printing 8x10 fotokemica emaks grade 3, a 50mm f2.8 el-nikkor stopped down to 5.6 and a beseler mx45 with a zone 6 cold light head.

    Luckily I spend a while tonight taking my Dichro 45 color head apart and found what was wrong with it. I'm excited to try printing the same negative with this head which I think is much brighter. I just hope the vibration from the fan isn't too severe.

    There is still a problem with my color head, the cam or gear for the yellow filter is slipping on the axle and won't move out of the light path without flipping the switch to move all the filters together so I can't use it for VC paper till I fix it. Any suggestions?
     
  14. ic-racer

    ic-racer Member

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    Lens focal length does not affect exposure per the first law of thermodynamics. Perhaps your meter is off axis to get 0.85 stops difference when you measure.
     
  15. Ian C

    Ian C Member

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    The difference was calculated, not measured, in post #9.

    Your comments prodded me to measure the difference.

    I focused a 35mm negative using a 50mm lens to cover the width (short dimension) of an upside-down scrap print at about 5.5” projection width and placed my meter on the print with the diffuser at the center facing up. I used ASA 1000 and 2 seconds and got a reading of f/8 + 0.4f.

    Then I redid this with a 90mm lens. Both lenses set at f/5.6. The reading was f/8 + 0.1f, so the actual measured difference was 0.3f. My calculated value didn’t agree.

    Then I reviewed the calculations I’d used. I had erroneously used an equation for the SAME focal length lens at different projection distances. This doesn’t apply to two lenses of different focal lengths.

    I promptly self-administered a “dope slap” for carelessness.

    Thanks for catching the error.
     
  16. Chris Douglas

    Chris Douglas Member

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    Same problem..

    I had the same problem with my Beseler 23, with dichro head. When using the diffusion set up, black and white took 90 to 120 seconds, and color took about 20 seconds. Apparently color paper is more sensitive. So, I use the condensor set up for B & W, and the diffusion set up for color. With the condensor, exposure times for B & W are about 20 seconds.
    I don't know it the condensor set up is possible on the Beseler 45, but someone else should know. Good luck.
     
  17. phfitz

    phfitz Member

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    "Lens focal length does not affect exposure per the first law of thermodynamics. Perhaps your meter is off axis to get 0.85 stops difference when you measure."

    35mm > 5x7 print
    how much bellows extension for the 50mm lens?
    how much bellows extension for the 90mm lens?
    how much exposure compensation for each?

    the 90mm with naturally make a smaller print size so less extension / compensation.
    I guess this will need a side by side comparison to prove out.

    "I don't know it the condensor set up is possible on the Beseler 45, but someone else should know."

    There are a few at eBay right now. Get the cheapest complete unit, they are all the same. Rather heavy for shipping, work very well. Condition, condition, condition.
     
  18. ic-racer

    ic-racer Member

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    Bellows factor is the same for both lenses (magnification does not change).
     
    Last edited by a moderator: Oct 11, 2011
  19. Photo Engineer

    Photo Engineer Subscriber

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    I have 3 mixing chambers for my Dichro! I guess Besseler quit making the others.

    As for Cyan filtration, it has no effect EXCEPT to cause long printing times! Cyan filtration must ALWAYS be set to zero.

    I get 12" at f11 for an 8x10 from 35mm. This is with a 35mm chamber. I get the same from 4x5 to 8x10 with a 4x5 chamber. This is with a 30M which is what the manual with it says is grade 2 for Ilford paper. The chambers vary from 35 - 120 - 4x5 by about one stop steps.

    PE
     
  20. ic-racer

    ic-racer Member

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    It should have no effect on printing time. It (should) block light to which the paper has no sensitivity.
     
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  21. ic-racer

    ic-racer Member

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    The following is a superimposed curve of Ilford MG paper and a cyan dichroic filter. The black lines represent different threshold density on the paper plotted against light wavelength. The colored lines represent transmission at different angles on incidence. In enlargers the angle of incidence will be zero degrees, so look at the BLUE curve to compare with the paper curve. As you can see the cyan filter will have very little on the paper, even when it is fully in the light beam. The filter shown passes over 90% of the useful light energy to the paper.
    [​IMG]
     
    Last edited by a moderator: Oct 11, 2011
  22. Photo Engineer

    Photo Engineer Subscriber

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    Generally, cyan filters have a considerable amount of absorption in the Green and Blue regions of the spectrum, thereby increasing effective exposure times. Even "pure" dichroic filters will suffer from this problem to some extent. Take a look at the spectral response of a common cyan filter someday if you get a chance. It is quite a surprise if you have never seen one before.

    After looking at your curves, I feel I should add that the angle of incidence due to the light box, is probably not zero degrees and that is why you might experience the problem that I describe. It is seen in your red or cyan curves where what I describe above is manifesting itself.

    PE
     
    Last edited by a moderator: Oct 11, 2011
  23. ic-racer

    ic-racer Member

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    Good point about the angle of incidence. Though, to eliminate said concerns, most enlargers that I am familiar with have the dichroic filters in the collimated light path before the light box, to get that straight-on shot from the lamp/reflector.
     
  24. Photo Engineer

    Photo Engineer Subscriber

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    I would have to disassemble the boxes, but IIRC, there is a 45 degree beam splitter in the system. I'll take a look at one of mine.

    PE
     
  25. phfitz

    phfitz Member

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    if you are still interested there is a 35mm mixing box at eBay now #380376800642
    nothing to do with it, just found it
    have fun with the hunt.