Enlaging 6x6 with a 150mm lens bad?

DraganB

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hi friends,

when i enlarge a 6x6 neg with my 150mm lens will there be some negative impact or just light loss and longer exposure & smaller print size?

thx for help
 

koraks

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No bad influence. No light loss either provided the same aperture is used (f/8 remains f/8 regardless of focal length!) Just a limitation of the maximum print size you can manage due to column height and bellows draw.
 

Sirius Glass

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I have used both the 135mm lens and a 150mm lens to enlarge 4"x5" film sheets and the only difference I noticed was the high the enlarge was raised from the paper.
 

Maris

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My standard enlargement size is a modest 8"x10" so I enlarge 6x6 negatives with a 135mm or 150mm lens. Advantages include:

The negative carrier goes into my enlarger at about eye level so it is easy to see it going in straight and level.
The enlarger head is further from the base board so there's room for a focus check with a grain magnifier without my head bumping the lens.
Only the centre of the lens's image circle is used. That's where the image is at its sharpest.
Minimal illumination fall off. The edge of the enlargement and the centre are nearly the same distance from the lens's exit pupil.
 

ic-racer

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Since you are only using the center of the lens image circle, the 'bad' lens might perform just fine.
 

RalphLambrecht

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DraganB said:
hi friends,

when i enlarge a 6x6 neg with my 150mm lens will there be some negative impact or just light loss and longer exposure & smaller print size?

thx for help
Click to expand...

there might be some vignetting, as the 6x6 negative usually requires a wide-angle lens, such as an 80mm enlarging lens; the rule of thumb is the negative format's diagonal or 'normal' focal length.
 

MattKing

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A 150mm f/5.6 lens - for example - isn't exactly bright when you are composing and focusing. And if your negative is dense, and you want to use f/5.6 to keep the exposure time reasonable, using it wide open may not be optimal.
But it certainly would be usable
 

koraks

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RalphLambrecht said:
there might be some vignetting
Click to expand...

Please explain how there'll be vignetting when enlarging a 6x6cm with a 150mm but if you enlarge a 6x6cm crop of the center of a 4x5" sheet this doesn't happen. If anything, a wide angle lens would induce vignetting because of the angle of the light towards the corner; a problem you don't have with a longer lens. Not that I'd call an 80mm 'wide angle' to begin with, btw. Not when enlarging 6x6cm in any case.
Maybe I'm missing something crucial that I've never noticed when enlarging smaller film with longer lenses; please enlighten me (especially the corners).
 

Pieter12

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No problem. You just won’t be able to make large prints, say 16x20, depending on how much distance you can put between the enlarger head and the easel.
 

miha

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RalphLambrecht said:
there might be some vignetting, as the 6x6 negative usually requires a wide-angle lens, such as an 80mm enlarging lens; the rule of thumb is the negative format's diagonal or 'normal' focal length.
Click to expand...

I would thought the other way around?
 

Ian Grant

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There maybe a slight drop in contrast compared to an 80mm. This is due to the longer exposures required, and the paper's reciprocity failure.
Some years ago I was given two turrets full of Compmponon (& S) enlarger lenses by my local pro lab, who had switched from roll-head printers to a mini-lab. Each turret contained 50mm, 80mm, 105mm & 135mm lenses, used for 35mm & 120 negatives. The degree of enlargement was determined by the focal length chosen.

Terry had worked for Pavelle/Durst UK as a technician and explained that each turret was set up and the lens apertures locked with a grub screw so all the lenses gave exactly the same exposure time, this ensured consistent contrast and colour balance regardless of the print size. You see the same change in contrast with B&W papers

Echoing Matt's points a 10"x8" print off a 6x6 negative with a 150mm is equivalent to a 20"x16" print (approx) off a 5"x4" negative with the same lens. It's making it all a bit harder,

Ian
 
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RalphLambrecht

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Ian, your comment made me unsure and I have to think about it again before digging this hole any deeper.
 

ic-racer

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miha said:
I would thought the other way around?
Click to expand...

It is the other way around.

Red line indicates relative illumination at the corner of an 80x80 negative compared to the center at varoious aperture numbers at high and low magnification. Even wide open the falloff is the same as stopped down with 4x5" negative.

 
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Randy Stewart

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Apart from the three negative attributes originally mentioned, there is the factor of lens resolution. A long focal length lens will usually have a bit lesser resolution than the shorter. This results from being designed to cover a much larger negative size/area. The differences are not normally apparent in a print. By far the biggest issue is going to be the inconvenience of having your enlarging potential limited to small print sizes, everything else being equal. Low light level of the smaller maximum aperture of the long lens will be offset by use of a good grain focus device, whatever lens you use.
 

Eric Rose

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To hell with all the techno babble. Just try it and see what you get. I routinely used 135 and 150 lenses to enlarge 6x6 negs. The prints produced were stunning in detail and contrast. The longer lenses also give you more room for dodging and burning gymnastics. My enlarger was very and I mean rock solid steady to reduce vibration.
 

btaylor

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I was printing 6x7cm negs yesterday to 5x8”. Using the 80mm lens the lens/head assembly was difficult to work around so close to the baseboard. So I switched the 80mm for my 150mm. Much better. Plenty of space. Exposure times went from 8 sec @ f11 to 14 sec @ f8, so no reciprocity failure. No detectable loss of sharpness, vignetting, etc.
 

ic-racer

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Eric Rose and btaylor got it. Depending on your enlarger and favorite printing size, the head and negative cairrage can be an obstruction. Like them, I use a long lens for 6x6 printing so I have more room between the lens and the paper.
 
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