Schneider 550mm XXL Fine Art lens

[Lukas Werth]

First to Bernard's question: I really can't imagine that there will be any gain whatsoever in quality in a scanned 11x14 over a scanned 8x10, not in tonal quality, not in sharpness, whichever lens may be used.

This brings me, second, to a somewhat critical remark about the discussion in this string: I don't want to hurt anybody's feelings, but I wonder if over this all this technical drooling and efforts of measuring the whole quality and charme of ULF is not missed. I don't think there is a definitely measurable advantage for many ULF's at all. The real mystique of these formats comes through the subtle possibilities of personal interpretation, of finding an adequate language for rendering subtle elements of reality - or something beyond quite that, by unbeatable contrast range and tonality, matched by a process of choice, and, yes, this nearly three-dimensional concreteness of a well-made contact-copy is also brought out by sharpness of details - but all this is more a matter of personal interpretation than objective technical possibilities, more a question of knowing how to handle a tool for a certain purpose - or rather, vision - than obtaining the latest gadget. For a given purpose, an old petzval lens may be as or more adequate than a new Schneider lens.

Sorry if this sounds somewhat mystifying, but when reading this string I was strikingly reminded of the technical rave of 35 mm cameras before the advent of digital, when the common perception was newer meant better (as nowadays with digital). I find it sobering to remember that the earliest proceses of all, calotypes and daguerrotypes, are able to deliver pictures of a quality which cannot be surpassed even today.

Lukas

[kreig]

After reading both the View Camera artical and all the posts here, I have one question: How does diffraction affect the 1100XXL? At what f/stop does the lens perform best, and what is the results of useing this lens at the smallest possible setting of f/128??

Ok, ok, ok, 3 questions.

Kreig

[Michael Mutmansky]

Kreig,

The lens is just like every other lens in that the diffraction will act upon it increasingly as the aperture increases (as the physical size of the aperture decreases). The lens will probably perform best at f22, and smaller apertures will show an increase in diffraction sharpness reduction.

However, this is an almost meaningless aspect for contact printing, because at normal apertures, the sharpness loss is not going to lower the lens performance below that necessary for contact printing. When closed all the way down, there may be enough of a reduction that it would be visible, but this is a bit different from an unsharp enlarged print, and still may be considered acceptable, depending on your requirements and tolerance levels.

For example, if you contact print on silver paper, the paper will be able to resolve better than if you print on a hand coated alternative process. While the sharpness loss may not be noticed on a pt/pd print, it may be noticed on a silver gelatin print.

There are formulas out there to calculate diffraction limits and other related performance variables, but I am not terribly interested in the actual values, and I don't think the typical photographer should be either. It's much more important to understand what diffraction is, what it does, and how to avoid it. Then, apply that knowledge to the photography as best possible given the shooting conditions.

---Michael