 Jon White |
Darkroom technique 120 film Hi all, I have just joined but cant seem to find the answer to this question. I have a darkroom at home- 135 mm no probs, taken, tanked, developed and printed. I have had some 120 films done at the local shop. I did not have a holder on teh durst M305 I use so I made one. When setting up it looks great but when I runa test strip at 2,4,6,8,10 etc a5, 20 up to 1 min , then develop the strip it comes up very dark and darkens in degrees up the scale. Sugestions please. Jon
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Mark Feldstein |
Hi Jon. I'm not sure I understand your question. As I recall, that's a warm head, condenser enlarger. You kind of say that your test strips are turning out too dark?? Try shorter exposures or determine whether the density of the negative at the top end of the strip is the same density as that portion getting exposure at the bottom end. Seewhatimeanhuh? It doesn't sound like there's anything wrong with either your technique or enlarger. Just adjust your exposure time and see what happens. Mark
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Pete H |
Sounds like you need to stop down the enlarger lens. You might look for a nifty little gadget I used back in my B&W days. LOL Place this simple device over your paper prior to exposing. Pete
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Mark Feldstein |
Yeah, I remember those things Pete mentioned. Kodak made them, and they were about 4x5" and you could slide them into a speed easel. Bet they still make them. M/
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Jon White |
Dear All thanks for the suggestions. Ill try going down to 4.5 and then exposing at 1,2,3 etc.Then ill try to simulate the kodak gaget. One thought though, would the grain on the 120 film be so tight compared to the 135mm film that I should be usinga different lens on teh enlarger? The thing against this is that the picture shows up really well on the easal. Many thanks and Ill give ita go tomorrow . Jon
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Christopher A. Vedros |
Jon, When you say you will try going down to 4.5, are you talking about the aperture on the enlarger lens? If so, you want to go UP in f-stops. Remember, low f-number = large aperture, high f-number = small aperture. If your test strips are too dark, you are getting too much light on the paper, so your aperture is too large. It's been almost 20 years since I worked in a darkroom, but I think we generally kept the enlarger lens aperture at about f8. Chris
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doug Nelson |
For 120 film, you ought to be using a 75mm enlarging lens. They are dirt cheap on eBay these days. You might also check for a 6 x 6/6 x 4.5 negative carrier for your enlarger. The Durst M305 is not a 35mm only enlarger is it? Any Durst users out there?
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Jon White |
Doug and Chris, Many thanks. I will go from F8 working upwards and various exposures. As to the lens it is currently a 1:45 f=50mm minolta (E.Rokkor). Ill give it a try tomorrow. Take your point on teh lens- thought that may have an effect with 120 film. Sorry to have tested the old grey history cells! Jon
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Bob Chance |
Jon: That would have been my first question to you was whether or not you changed the lens on the enlager for doing the 120. The lens you should have been using for 35mm doesn't have the coverage needed. It's like trying to use a lens from a 35mm camera on a medium format camera, only backwards. The image projected by such a lens wouldn't completely cover the 120 negative. Likewise, the lens you use for printing 35mm can't see the entire 120mm negative. Basically what you are suffering from is vignetting. The outer edges are being cut off because the lens doesn't have the coverage angle to see the entire negative. Bob
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Michael H. Cothran |
You WILL need an appropriate size enlarging lens for 120 film. An "appropriate" size enlarging lens EQUALS the lens focal length considered to be "normal" on the camera. Thus, for 35mm film = 50mm enlarging lens, 645 neg = 75mm enlarging lens, 6x6 = 80mm lens, and 6x7/6x8/6x9, = 100mm-135mm lens. FYI - Ansel Adams used to preach that one should actually use an enlarging lens LONGER than the normal. Basically this means using an 80mm enlarging lens for 35mm film, and a 135mm enlarging lens for 120. This limits the size enlargements you can make, since the lens has to be raised higher for each given print size. Michael H. Cothran
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Jon White |
Dear All, I did not know the bit on Adams and I will use that in my next essay. Likewise the maths has gone into the memory bank as well! I seem to have it cracked now. Please keep the thread going as I am sure I will not be the only one making mistakes like this and it would show up in a google search. Jon White
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Andrew Laverghetta |
Just a quick question to you, was your homemade 120 negative carrier directly in the center of the enlarger? I had a problem like this one before my teacher could actually get me a real 120 negative carrier. It was really hard to keep it centered since it didn't have the notches.
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