Enlarger lens question

[astrosecret]

I just purchased an enlarger locally and guess i didn't do all my homework. it came with a 105mm lens for 6x7 negatives, and i was about to buy a 50mm lens for my 35mm negs. however on the enlarger (rolleimat) it states i would need a different model condenser (condenser 1 as opposed to condenser 2, which it came with) to print with a 50mm lens.

with the current condenser, i am able to make prints just up to about 7x9 with the enlarger head racked all the way up. if i did decide to throw on a 50mm lens, would that maximum print size go up or down? I really just want to be able to print 8x10s.

 

[Fawley]

I have read that the purpose of the condenser is to focus the light in the aperture of the enlarger lense. So if you have the wrong condenser, I think you may have a problem with not throwing light over a large enough area to make the print size you want. I would simply try it and see if you can make the print size you want.

 

[astrosecret]

i see. so theoretically i may get vignetting and fall off if i were to use a lens not spec'd for it? to be clear, the condenser i have is used for 6x6/6x7 negatives, and the largest 35mm prints i am able to make are around 6x8. I want to be able to do 8x10 with 35mm negs. thanks!

 

[Freakscene]

With the medium format condenser all you're likely to end up with is a slightly dimmer image and longer paper exposures. The condenser for 35 mm will focus the light in a narrower cone and send a greater proportion of it through the lens. Particularly if you can borrow or get a cheap 50 mm enlarging lens I think it's worth trying with the condenser you have. Finding some enlarger parts is easy, but for some it's hard or amazingly expensive (especially Durst).

Marty

 

[astrosecret]

Thanks. won't i be able to compensate for the dim image with longer exposure times or maybe a faster lens, ie 2.8 as opposed to 4? I can also safely use a 75mm lens with this condenser the manufacturer says. what i'm wondering is, as i go down in lens length, will the projected 35mm image become larger or smaller with my medium format condensor

 

[tj01]

If you are doing 8x10, then an 80mm lens should get you up to 65cm height from paper to negative. Will that be high enough for you ? Otherwise get the 50mm, but that might mean the lensboard needs to be very close to the negs, which requires a different sunken lensboard.
Though your current condenser is bigger , it's not optimum. But completely acceptable.

 

[Freakscene]

In practice printing at 20 s instead of 10 s exposure makes very little difference. The difference might not even be that much. And yes, of course, you can print at f2.8 or f4 instead of f5.6 or f8, as long as your enlarging lens is good enough at those wide apertures (it will be if you get a good one).

And yes, the issue of the lens board and needing a recessed one with a 50 mm lens may arise. A 75 mm lens should also let you print at 8x10.

Marty

 

[astrosecret]

thanks all

i think i will try out a quality nikkor 50/2.8 and if problems arise, i'll look for a 75mm. i'll update this thread with my findings since there may be somene else who also comes across a rolleimat in the future, and hopefully this thread can answer their questions.

 

[ErnestoJL]

If you have an enlarger for MF, you have a condenser designed to provide even lighting over a big area of about 90 to 110 mm in diameter. Then if you use a 35 mm mask you´re only getting a fraction of the total available light. That´s why you need to expose for a longer time. I have an enlarger for 35mm up to 6x9 and illumination is good for 35 mm, and shows a slight fall off in the corners when enlarging big negs.
IMHO, you shouldn´t have any problems enlarging 35 mm negs. The only that would come out is that the bellows minimum extension couldn´t be short enough for a 50 mm lens, and that requires a recessed lens mount or using another longer lens to solve the problem. Thus you would be limited to a certain max copy size.
Cheers
Ernesto