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Lenses for 12x20
Hi to everybody:
I will appreciate if someone could give me a run down on what lenses are appropi ate for a 12x20 large format camera. I am looking for a 450 or 480mm; 600mm and perhaps a 350mm.
I am interested in either new lenses or old lenses.
Also, I was wondering what is important to look for when shopping for a 12x20 l ens, is it the image of the circle or the angle of coverage?
Best regards to all,
Alejandro
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Lenses for 12x20
Ya might start here:
http://www.wisner.com/20x24lens.htm
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Lenses for 12x20
I think that the Nikkor 360W and Fuji 600C may offer sufficient coverage for this format. A reference for lenses covering 11x14 is here, and some of these will cover 12x20. This is a format I firmly intend to get into.
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Lenses for 12x20
Don't mistake angle of coverage for angle of view.
If I'm not mistaken, the image circle is directly proportional to the angle of coverage --> if the image cirle covers the format, the angle of coverage will cover and visa-versa.
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Lenses for 12x20
Friend of mine have a couple of 25" f/9-256 Rodestock Apo-Ronar in barrel for sale.
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Lenses for 12x20
For modern lenses, Schneider G-Claron 355/9, when stopped down to f45, will cover 12x20 with an inch or so movements in each direction. You will be more confortable with new Fujinon 450 and 600. For old lenses, you might want to look at Dagors. A C. P. Goerz rectagon 270/10 will also cover 12x20. Write to Carl Weese for export advices.
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Lenses for 12x20
Hello Geoffrey:
Where do I find Carl Weese?
I prefer to be more confortable, so: How much movement would I have with the Fujinon 450? (Is this the same lens as: Fujinon CM-W 450?)
How about the Nikkor 450M, is it a suitable lens for a 12x20?
Regards,
Alejandro
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Lenses for 12x20
Carl is on the forum. Check some threads about ultra large format. That's his specialty. Maybe someone else knows his email address. Good luck!
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Lenses for 12x20
Alejandro,
Check here: http://home.earthlink.net/~cweese/
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Lenses for 12x20
Alejandro, One of the problems to deal with in 12X20 (besides equipment size and weight, and film cost) is finding lenses to cover the format. I measured a 12X20 holder - the diagonal is 23" or a little more, so you need at least that large an image circle. A larger circle is needed to have room for movements. Go to http://www.wisner.com/lenscov.htm and look at the column for 12X20. The numbers Mr. Wisner gives are degree of coverage needed in order for a particular focal length to be able to cover 12X20. Different lens designs have different degrees of coverage.Goerz Dagors (depending on vintage) have an 87 to 90 degree of coverage (one of the reasons Dagors are highly thought of by LF photographers). Reading down the column, a 305mm focal length is the shortest FL that will cover. In order to have room for movements, choosing a 14" (360mm) Dagor would be better. A 16 1/2" or 19" Dagor would give even more coverage, but as the focal length of Dagors increases, they become much more difficult to find (and more expensive). If you think you may want to someday move up to 16X20 format, you can use the longer Dagors. http://www.lensrepro.com/ is one source for older lenses like Dagors. The 450mm Nikkor (I believe) has a coverage angle of 60 degrees. By Mr. Wisner's chart, a 60 degree lens would need to have a FL of more than 480mm to cover 12X20, so it doesn't look likely the Nikkor will work. Goerz Artars cover about 45 to 47 degrees - hence the common 24" (600mm) Artar doesn't look like it should cover, although I've heard people claim it will. The next longer Artar shown in my Goerz catalog is a 30". Do you have enough bellows length? Protars covered a little less than Dagors - I believe a 14" or longer Protar would work, but I'm not that familiar with Protars. If you haven't already, look at all the Q&A part of Mr. Wisner's site, including the archive of older questions. Also http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=004BTg and http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=0004YH