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This seller on the auction site claims incredable coverage for lenses. My experience is not consistant with his claims. Opinions? Item 220401446141, I have a 21-1/4 ektanon which will cover 12x20 ( my experience ) at F:22. This claim for the 17-inch seams a stretch. Enlighten me, Craig
Hey Craig,
I have data from the 1967 Burke & James catalog that says the 17" Copy Ektanon covers 14x17 "stopped down". There is no specific f/stop given. Since this data does not come from a Kodak published source, I would take it with a grain of salt.
Wouldn't be impossible but you can't tell without knowing what the angle of field is of the lens.
A 360mm Apo Ronar CL covered 14x18" at 1:1 at f22 and the 480mm Apo Ronar CL covered 18x24" at 1:1 at 22. On the other hand the wide field Apo Gerogon 360mm covered 24x30" at 1:1 at f22.
The Apo Gerogon series covered between 70 and 78° depending on the focal length and the Apo Ronar CL covered 48° for lenses up to 480mm.
So you need one more piece of information. What is the angle of field of the lens in question.
http://www.largeformatphotography.in...p/t-37668.html
http://www.largeformatphotography.in...p/t-16161.html
http://www.largeformatphotography.in...d.php?p=131915
http://www.mamutphoto.com/forum/inde...pic=215.msg913
If the 17" Ektanon is the same design as the 21.25" Ektanon, I wouldn't expect it to cover 12x20, let alone 16x20 as the fleabay seller suggests. Unfortunately, no expert on the Anastigmats/Copying Ektanons has stepped forward to opine on their coverage and any differences between the focal lengths.
I also think, at this late date, that there really are no "secret" ULF lenses: if the 17" Ektanon could cover 16x20 for the prices it fetches, everyone shooting 12x20, 14x17, and 16x20 would own one and sing its praises. And it would inevitably come up in the occasional 20x24 threads, where 16x20 lenses are recommended for "studio" distances.
My 19 3/4" Copying Ektanon and 19 3/4" Eastman Anastigmat both cover 12x20.
No experience with a 17"
Charley