Condensor format question

[Cinema]

hi all, i'm new here. i posted this question on RF forums and looking for an answer on the interwebs, came across this community. Thanks in advance for your help.

"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.

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 6x8in. I want to be able to do 8x10 with 35mm negs. thanks!"

 

[MattKing]

Welcome to APUG!

You might get a more complete answer if you mentioned which model of enlarger it is.

That being said, most likely the medium format condensor will work fairly well with a 50mm lens for 35mm negatives.

The condensers concentrate the light path, in order to minimize flare and keep exposure times short. With a 35mm negative in the larger, medium-format light path, some of the light will be wasted outside of the negative area. That wasted light may add a bit of flare, but mostly it will just mean you will have longer printing times.

If you are just enlarging to 8x10, the longer printing times will most likely not bother you at all.

If it was the other way around (you had the 35mm condensor, but wanted to print medium format) then it wouldn't work - the light wouldn't be even enough for the corners of the negatives.

 

[AgX]

With a point-light source the condensor must be apt and adjusted for the format and scale of enlarging.

With a large light source (opalized bulb or diffusion chamber) combined with a condensor it is more a question of effective light output.

 

[George Collier]

If I was you, I would try to borrow a 50mm lens that fits the mount and try the existing condenser set. I had an old Lucky enlarger in the 60's that I used for 2 1/4 square and 35mm. The condenser was for the 2 1/4, but worked fine for the 35mm. As Matt points out, I probably had longer exposures as I would have with the right condenser, but I didn't know the difference and went on happily with it. With 8x10, it likely would be enough.
You don't mention your location, but an Apugger might lend you a 50 if the mount is right.

 

[Andreas]

Just to make sure there are no mistakes here: The condenser is there to concentrate the light and give even illumination. It has no influence on the picture size on the baseboard. The focal length of the enlarging lens determins the picture size on the baseboard (for a given elevation of the enlarger head). You should have the right focal length for your negative size: 50mm for 24x36mm, 75 or 80mm for 6x6cm (2 1/4 in square) and 100 or 105mm for 6x7cm. You could use the next longer focal length, but that will give you less enlargement. You can't use a shorter than normal focal length for a given negative size, that would lead to severe light falloff and unsharpness at the corners.
Good luck
Andreas

 

[fotch]

Hello Cinema and welcome to APUG. The head will work for 35mm with a 50mm lens, just won't be as bright as it would be with the appropriate condenser. That said, probably will be bright enough, good luck.

 

[AgX]

Sorry Cinema, in case my post #3 was ambiguous as Andreas hinted at.

I'm not a native speaker. I guess I should have chosen my wording better and written that the condensor in certain case has to be adjusted to the chosen scale of enlargement. One cannot adjust the scale of enlargement by manipulating the condensor.

 

[Cinema]

Thanks all, I'm very happy to hear that this will work. Even though I have been wet printing for a while, it's obvious I don't know the basic mechanics of the tools i'm using! Thanks for explaining the actual role of a condenser to me. I have ordered a 50mm lens and am hoping it will fit the enlarger. If not I think I may be stuck at 75mm for now and I will have to find one of those. I will update this thread with how it turns out.

Cheers

 

[Cinema]

I received the nikon 50mm lens today and threaded it in-sucess! for others curious about this combination in the future, note that the rolleimat universal w/ condensor 2 will work with 50mm lenses without modification. I am able to make prints up to about 11x14 now, maybe a little bit smaller. it is obviously a little dim, but this is not really an issue. especially with the relatively fast lens i'm using, the nikon f/2.8. There is vignetting but it is outside of the 35mm area. Thanks to everyone who replied