optics question

[Drew Wiley]

Pere, I didn't have time at that moment to qualify my statement that other factors were no doubt cumulatively involved. AA's film plane was never truly flat, and his enlarger was primitive (the largest prints were contracted out to a commercial lab and printed under his supervision). The films were much grainier than today. Camera shake would be obvious; but huge shutters have a more subtle effect. Still, I doubt the convertible lenses of that period were in the same sharpness league of modern lenses. Gel filters probably help much either, esp behind the lens.

[Drew Wiley]

Gels probably DIDN'T help. Scuse me. But since those lenses weren't even close to apochromatic, certain filters probably exaggerated a halo. Even the Wisner casket set had a problem with blue light, requiring a yellow cutoff filter. I'd imagine Cooke these days has excellent control; but you pay for it.

[Pere Casals]

Drew, with the sharp Aspen you cite ( "Aspens, Northern New Mexico," 1958 ?) Ansel used the 19" (480 mm) component alone of the Cooke triple convertible. This may show a perfomance level for converted configurations.

[xkaes]

IMHO in LF a zoom is less needed because you always can crop and still having IQ in excess, smaller formats have severe IQ problems when making a crop...

I can't remember the last time I made a print from a 4x5 negative without cropping at least a little. And many times I have cropped a lot -- although some purists consider any amount of cropping a mortal sin. But the same goes for all of my smaller formats -- often to fit a paper format -- but I also frequently crop the paper to fit the subject. That means my results are largely "subject driven" and not film or paper driven. You have to do that if you love panoramas!

[Pere Casals]

I can't remember the last time I made a print from a 4x5 negative without cropping at least a little. And many times I have cropped a lot -- although some purists consider any amount of cropping a mortal sin. But the same goes for all of my smaller formats -- often to fit a paper format -- but I also frequently crop the paper to fit the subject. That means my results are largely "subject driven" and not film or paper driven. You have to do that if you love panoramas!

Well, we are free to crop or not. What is clear is that if wanting a particular composition with a particular perspective we may need an intermetiate focal that we don't have, then single solution is to crop as zooms are not "popular" in LF... and zooms are ot necessary in LF because we can crop and still having lots of IQ. Single question is if we have a lens kit with +30% or +50% progression. Anyway best may be having a single lens and exploting it Perhaps it is the way to get better photographs.

[Jody_S]

From Wikipedia:

“The first true zoom lens, which retained near-sharp focus while the effective focal length of the lens assembly was changed, was patented in 1902 by Clile C. Allen (U.S. Patent 696,788). An early use of the zoom lens in cinema can be seen in the opening shot of the movie "It" starring Clara Bow, from 1927.”

Well that's what I get for not checking exhaustively before hitting 'reply' on this forum. I thought commercially-successful zooms started showing up in the late 1950s, but never bothered checking when the first design was patented. Completely irrelevant to the discussion, of course.

[Bob Salomon]

Well that's what I get for not checking exhaustively before hitting 'reply' on this forum. I thought commercially-successful zooms started showing up in the late 1950s, but never bothered checking when the first design was patented. Completely irrelevant to the discussion, of course.

Not if zoom lenses were being used in the 20s!

[Alan Gales]

IMHO in LF a zoom is less needed because you always can crop and still having IQ in excess, smaller formats have severe IQ problems when making a crop...

Pere, you have a valid point. It would of course all depend upon how good the zoom was. I remember when zoom lenses first came out for 35mm and they couldn't match a fixed focal length lens at all.

Just be careful mentioning cropping though. I once mentioned on one of the forums using a wide lens on 8x10 that didn't quite cover and cropping out the darkened corners. I got jumped on! "What, why shoot 8x10 if you are going to crop?".

[Bernice Loui]

Lenses that do not properly cover 8x10 is often due to the image maker using a lens that is not designed for 8x10 or is using a lens designed for 8x10 beyond it's design limits.

Brings up, why not simply go to a smaller format where lens choices are FAR greater and overall lower cost?


As for LF zoom, is there really a need?

Change is focal length (Wide, Normal, Tele) is directly related to front to back perspective size. Many smaller format (including digital) image makers use zoom lenses to fame an image intended from where they stand rather than moving to a image making location that results in the image intended. Granted this is not possible in all image making cases, but can apply to many image making using any camera. Serious film and video folks expend an awful lot of effort to set up the image making location and apply what is needed to achieve the desired image effect.

Zoom lens scene from Kubrick's Clock Work Orange opening. Combination of a modified Angenieux 12-240mm f3.5 on a Mitchell 35mm camera pulled on a rail cart.
https://www.youtube.com/watch?v=kTuuXL8lakE


Bernice

Pere, you have a valid point. It would of course all depend upon how good the zoom was. I remember when zoom lenses first came out for 35mm and they couldn't match a fixed focal length lens at all.

Just be careful mentioning cropping though. I once mentioned on one of the forums using a wide lens on 8x10 that didn't quite cover and cropping out the darkened corners. I got jumped on! "What, why shoot 8x10 if you are going to crop?".

[xkaes]

Just be careful mentioning cropping though. I once mentioned on one of the forums using a wide lens on 8x10 that didn't quite cover and cropping out the darkened corners. I got jumped on! "What, why shoot 8x10 if you are going to crop?".

I tried to warn you.

I once made an 1x5 FOOT panorama on the Mogollon Rim in Arizona from a 1x5" section of a 4x5" negative (Agfapan 25) with a 65mm Fujinon SWD. My large format class was blow away by the quality and could not figure out how I did it. The professor never taught us about the importance of cropping, but all the students learned about it.