enlarging lens focal length / negative size

[temujin]

i am getting ready to set up a home darkroom, and need to determine what enlarging lens(es) to buy. i shoot medium format, in both the 6x7 and 6x4.5 negative formats. i have read that the proper enlarging lens for 6x7 is 105mm or 100mm, while for 6x4.5 it is 80mm or 75mm. my question is: if i buy only a 105mm enlarging lens, will it also give me good prints from 6x4.5 negs, or do i also need to buy a 80mm lens for the 6x4.5 stuff? thanks.

 

[Nick Zentena]

If you're enlarger can handle the size print you want a bigger lens will work fine.

OTOH most 80mm will handle 6x7 just fine.

 

[Steve Smith]

I agree. I have an 80mm which I use for 6x6, 6x4.5 and 35mm and I'm sure it would be o.k. for 6x7. I have however recently bought a 105mm and I expect that will now be used for everything unless I want a larger print from 35mm.

Steve.

 

[haris]

I use 80mm for 6x7, and many other printers too. No problem at all, just remember to use proper mixing chamber/condenser for negative size. So, you don't need 100 or 105 for 6x7, 80mm is good for 6x4,5, and 6x7.

 

[Chan Tran]

I even use the 80mm and 105mm lenses for 35mm when I want to make 4x5" print.

 

[fschifano]

Using a 105 mm enlarging lens for 6 x 4.5 negatives is no problem at all. The only caveat is that the maximum print size will be only 75% of the size you would be able to acheive with an 80mm lens. But as Nick wrote, an 80mm lens can work just fine for 6x7 and smaller negatives. I have a Schneider 80mm Componon-S that works well with 6x7 negatives even though Schneider doesn't recommend it for that application. If you can find one, and I'm not suggesting that this would be a difficult task, the 80mm EL Nikkors are rated for use with up to 6x7 negatives. I've used, but don't own, one of these lenses and it gives up nothing in terms of image or build quality to the 80mm Componon S.

Regarding light mixing boxes for diffusion enlargers, there is no need to obtain the smaller sizes if you already have the largest sized mixing box available for your machine. My enlarger has the 4x5 light box which I use for everything from 35mm to 4x5. Light boxes designed for smaller formats will concentrate more light onto a smaller aperture. You might gain a stop or so of light with correspondingly shorter exposure times, but other than that there is no difference0

 

[Steve Smith]

I have a Schneider 80mm Componon-S that works well with 6x7 negatives even though Schneider doesn't recommend it for that application.

That's what I've got. And I just spent money on a 105mm lens specifically for 6x7. I should have tried the 80mm first!

Steve.

 

[Anupam Basu]

Yes, it'll work fine unless you find the slightly limited magnification a problem. In fact I print with lenses slightly longet than normal for the format because I usually don't go above 8x10 or so.

-Anupam

 

[Woolliscroft]

That's what I've got. And I just spent money on a 105mm lens specifically for 6x7. I should have tried the 80mm first!

Steve.

Well if you ever get a 6 x 9 it will cover that too.

David.

 

[Chazzy]

Well if you ever get a 6 x 9 it will cover that too.

David.

A good excuse to go out and buy a classic folder, if ever I heard one!

 

[jstraw]

When I use an 80 for 6x6 the head is too low for my liking. When I use my 150, it's ok but I could be pretty limited if I wish to make bigger enlargements. I could use a 105 but I'd have to find another adjustable lens board for my MXT.

 

[craigclu]

I use 645 and 6X7. I have a good 80, 90 and 105 but the 90 APO is on the machine 90% of the time as it easily does 8X10 from 645 and naturally, handles the 6X7 at all sizes well, too. The only reason that I can think of to be concerned about the versatility of the 90 with 645 is if you have limits of enlarger height or ceiling height issues over your enlarging area, etc. With my equipment and darkroom, it seems to be the most versatile focal length for me.

 

[Buster6X6]

A good excuse to go out and buy a classic folder, if ever I heard one!

I just bought folder last fall.

I use 105 Componon-S from 6X9 to 6X6 works well with all formats.

 

[PeterB]

don't wider angle lenses exaggerate perspective and barrel distortion?

Using a 105 mm enlarging lens for 6 x 4.5 negatives is no problem at all. The only caveat is that the maximum print size will be only 75% of the size you would be able to acheive with an 80mm lens. But as Nick wrote, an 80mm lens can work just fine for 6x7 and smaller negatives.

I initially didn't think too hard before writing this but I decided to post the questions and my own answers anyway because others might benefit.

Why won't I see parallel lines converge more strongly with the wider angle lenses in an enlarger as one would in a camera? i.e. don't wider angle lenses exaggerate perspective and give barrel distortion? Everyone seems to suggest that it is only the image mangification that differs with different lenses (and not convergence effects).

Here are some answers to my questions, but before taking a peek here (at points 4 and 5), why not think about your own answers first .

So let me know if you got the right answer or not !

regards
Peter