Going from 75mm lens to 80mm for MF

cesrig · Dec 6, 2008

I made a few prints on a Beseler 23CIII enlarger with a 75mm lens, although I usually work with an identical enlarger with an 80mm lens. I need to make a few copies of the print that was made with the 75mm lens, but will the same exposure times carry over when I'm using my usual enlarger with the 80mm lens? I'm not even that clear on what the difference (is there an appreciable one?) between the two for printing medium format...

Thanks!

dancqu · Dec 6, 2008

I'd expect a little more time at same F stop given
same lamp intensity. Which 75, which 80?

BTW, not many have the 23CIII. How do you
like it? Any glaring weakness. Dan

jp80874 · Dec 7, 2008

There are other factors that will change how the final print appears. The chemistry may be different, older, newer, different temperature. I would suggest a test strip or a single print before I ran several prints and developed the bunch. A little preparation could save wasting the several.

John Powers

Claire Senft · Dec 7, 2008

The only differences will be in the exactness of the f stops and the differences in light transmission for the two lenses and contrast characteristics. Since you will be making the same sized print from the same negative your original exposure should be very close. In fact there may be no visual difference at all. Make one print and carefully check it out.

Mark Fisher · Dec 7, 2008

Claire is right....there is a certain amount of light going through the negative and hitting the paper either way. The 75mm will just have the head a little higher. As with most things in the darkroom, I suggest that you experiment a little and just try it. I've learned a lot more playing in the darkroom than listening to people on forums

cesrig · Dec 7, 2008

I'll give it a shot tonight. I like having a better idea of what to expect. Thanks for the responses!

Jason Mekeel · Dec 18, 2008

I believe 75mm is normal for 6x4.5, 80mm normal for 6x6, and 90mm normal for 6x7.

Going from 75mm lens to 80mm for MF

cesrig

dancqu

jp80874

Claire Senft

Mark Fisher

cesrig

Jason Mekeel

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