Lens for 12x20 / 20x24
Hi all, I know that this has probably been done to death, but it's a "help me find a lens" thread.
In short, I got some Kodalith 20x24 for ridiculously cheap, if I cut it up into 4x5s it costs about 3c a sheet.
But that's not what I want to do, having something so huge. I'm considering cutting it in half to 12x20", but no further (if i'm going to cut it to 10x12" I may as well just shoot 8x10 and be done with it).
Anyway, to start with, I'm going to be doing some pinholes, cardboard cameras and such, i'm already converting a suitcase and may do a wheelie-bin camera too.
But if I can swing it, I would really like to make my own camera with a real lens. Problem is, there's very little 'condensed' data on image-circles this big, like the data here in a nice usable table format, I've had to go digging around multitudes of places looking for datasheets to make my own table. So I've probably missed a few possibilites and avenues to investigate.
Anyway, so what I've found so far (in terms of what to look for on fleabay), with image circles above 600mm at infinity are:
Apo-Ronars (above 760mm)
Apo-Nikkors (above 360mm)
Plus a few of the largest Xenars, Componons, and Clarons should just cover 600mm. I'm also searching for old lenses like Dagors (and a 24" Heliar should cover but is probably pricey), that were made back when film this size was more popular, but I'm not expecting to get any cheaply. Given the slowness of the film, and the fact that I'm shooting landscapes stopped down, I'll just use a lenscap shutter, so process lenses are definitely possible.
The First question is: what other makes/models/brands could/should I be searching for? I've got ages to wait for a bargain, I'm just going to create a fleabay saved search and wait for something.
Historically significant rarities are out, just too expensive. I've seen the occasional 800mm Apo-Ronar go for $4-600, I'd like to keep my budget maximum there, $1000 is just out ("but honey, I need to spend $1000 on a lens to use the film that I bought for $40!" - not gonna happen).
I've seen Reinhold's meniscus lenses, they're definitely a possibility once I've convinced myself I'm not getting any better for the price.
(The Second question is: what can I get to cover the 47"-wide roll of agfa-ortho I got at the same time?
The Third question is: am I insane? That's an easy one to answer).
Look again at those Apo-Nikkor data - you were most likely looking at numbers for 1:1, not infinity. Divide in half.
Originally Posted by Dr Croubie
At the shorter end, the 355 G-Claron should just eke out 12x20 if you stop it way down. The 450 Nikkor M should comfortably cover 12x20, again stopped way down. With a bit of patience, either should be available in shutter for well under $1000. With a lot of patience, you might find the 355 G-Claron in barrel for a lot less.
A process lens will do the job just fine. My 610mm & 890mm Apo Nikkor lenses work incredibly well at infinity with the 890mm covering the 24"x32" plates I shoot easily. Mine cost $350 so just keep your eyes open. These dialyte lenses work ideally at f22. My 1200mm Apo Tessar will cover a lot more but cost $700 because more people are working in ULF now.
I've spoken to Reinhold quite a few times and encouraged him to make the 790mm f5.4 for my wet plate work, but of course (being a meniscus lens) they are soft wide open and sharpen up very well when stopped down.
You may find a nice Apo Artar for the right money but as soon as you want it mounted in a shutter watch the price soar. Heck, who needs a shutter anyway?!
610mm aero ektar will cover quite a bit too.
Look here http://sdrv.ms/1i4czGa for links to more catalogs than you'll want to read. Look up Apo-Nikkor and Apo-Ronar coverages, also Apo-Artars. Don't bother thinking about Apo-Saphirs, long ones are too uncommon. Don't forget Schneider's Fine Art XXLs, which will both more or less do for 12x20.
12x20 needs a lens with an image circle of at least (I rounded, don't quibble about a few lousy mm) 600 mm, 20x24 wants 800 mm. In Apo-Nikkors, a 760 is a bit short for 12x20, a 1200 or 1210 will do for 20x24. These aren't inexpensive.
Another example of the corrupting influence of found money, sorry, found film.
Thanks for all the suggestions guys.
I've checked the coverage of the ApoNikkors from Dan's links, looks like they only cover 42 degrees so I want 760/11 or up (you're right, the data I had was looking at 1:1, so was wikipedia's data, methinks me should edit it to clarify).
(coincidentally, there's an apo-nikkor 760/11 listed on the bay right now, wish me luck).
And yeah, it's going to be infinity only, so can't get away with smaller lenses.
Aero Ektars are one that I've heard of before but didn't think about including in this search, I'll have a look for them too.
You could try a Schneider Symmar 360/620 convertible. Schneider advertised them as suitable for 30x40cm, i.e. 12"x16", so there is a good chance that they would cover 12x20 at closer distances. They come and go regularly on eBay and it shouldn't be too hard to get a nice one in a working Compound IV for under $500 if you are patient. Once the Compound shutters stopped production they went to a Copal 3 and the coverage declined. The earlier Dagor version of the 360 Symmar will have even greater coverage but they are a lot rarer so you could be waiting a long time for one of those.
Don't waste your effort. USAF had cameras that shot 9" x 18", 18" x 18", and even a few larger but lenses for these monsters extremely hard to find, large, heavy and, nowadays, expensive. To get an idea of what to look for, go to the catalogs URL I gave you and look at USAF lenses.
Originally Posted by Dr Croubie
In this youtube video 20x24 studios talks about the lenses they use with the 20x24 Polaroid. One is a 600m Fujinon A that will just barely cover at infinity and the other is an 800mm Rodenstock process lens mounted in shutter.