Really simple question: does anyone know what the optimal enlargement performance range of the Schneider Apo-Componon HM lenses was? Been struggling to find the answer in most of the official literature.
Really simple question: does anyone know what the optimal enlargement performance range of the Schneider Apo-Componon HM lenses was? Been struggling to find the answer in most of the official literature.
Depends on the focal length. Be more specific.
The 90, 120, 150mm are the major ones of interest, however, the 40, 45 & 60 would also be handy to know. I'm mainly interested in what the specified maximum enlargement capability was.Originally Posted by Bob Salomon
If I recall correctly, they were optimized for 15x enlargements...at least for MF and LF, but perhaps Bob can just list the range for each focal length. In general, I would advise just using them...you are not really going to find many better enlarging lenses anyway, so if you want to print big, you might as well use them. The only lens I am aware of that might be better for huge murals would be the Rodagon G series.
Schneider don't provide this information, at least not in the 3-pager I have specific to the Apo-Componon-HM line. That publication does contain a table of lens-to-film distances for the "most common magnifications", ranging from 1x to 12x, so presumably the lenses will perform well at least over this range.
I don't know if "Schneider don't provides this information" as it was suggest. But, if you were some how able to view the information on your computer, it you will see the best performance (HM 45mm) was at 3 power magnification at f8.
You can retrieve Schneider's data sheets through this archived page:
https://web.archive.org/web/20050402...o-componon_hm/
The sheets don't explicitly state a recommended magnification range. MTF is shown at three magnifications, but there's no indication of how badly it falls off outside the extremes. Extrapolate at your own peril.
You also have the G-Componon for murals:
But I guess that they are not easy to find used (this points that Bob made a better commercial job with Rodagon G !)
Those lenses were sold until people proffesionally making murals moved to lightjets and lambdas.
yes... this is the good information. "Optimized for X" is very elastic information, those graphs explain very well what happens. Anyway we always have the sample to sample variation.
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IMHO a major feature of the HMs is that they are optimized for large aperture work, IMHO this is more important than the optimization of a particular magnification, if one does not make duplication.
From my point of view, optimization for large aperture work is today less important because we have to new resources: LED illumination and cheap Fresnels for solar energy. This allows powerful, easy and perfect illumination (with a controlled degree of diffusion) to illuminate murals.
Last edited by Pere Casals; 6-Aug-2019 at 16:57.
Do you have some particular focal length in mind?
They're only made up to 150, which would be the only true LF focal length. Most enlarger lenses (versus graphics lenses adapted for enlarging) are optimal sharpness about 1 to 2 stops down from maximum. But with 4x5 film, you're likely to have an appreciable amount of illumination falloff just one stop down, depending on your specific diffuser above the carrier. Magnification ratio is yet another issue, but not important unless you're anticipating really huge enlargements. Anywhere between 4X and 7X is probably ideal, with going somewhat bigger, like 12X, no problem either; but I'm estimating from memory based on charts seen quite a while back. And the best working aperture is going to be somewhere around f/8 to f/11, depending. These lenses were just Schneider's way of trying to keep up with the Jones' (i.e., Rodenstock's Apo Rodagon N series, which I know quite well from routine current usage). Most modern enlarging lenses are capable of a high degree of sharpness relative to their recommended format. What these pricier "Apo" ones do is render microtonality or micro-texture better in black and white prints and give them a rewarding bit of extra edge or subtlety. With color prints, they tend to give slightly higher contrast, which might or might not be desirable. I wouldn't recommend them for either mural work of 1:1 repro.
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