View Full Version : Lens for 14x17

Tadge Dryja
22-Jun-2004, 22:15
I think I'm going to try to build a 14x17 camera. I may try to use all or part of my 4x5 camera to hold the lens, get nice focusing control that way, and basically make some kind of back that attaches to that...

This isn't going to be anything fancy or nice looking, it's just for fun to play with over the summer, try some contact printing which people here say is good stuff, etc. So I'm looking for a lens that will cover 14x17 (somewhere around a 550mm image circle) but I don't want anything fancy or good or expensive. I'm betting that any lens this long in a shutter will be way expensive, so I'm not even looking for ones in shutters, just barrels. I do want an iris though.

Any reccomendations, ideas, etc? I'm not enlarging, I'm not going to be picky about lens quality, the thing is probably going to be used at like f/64 to f/90 anyway... but I do want a lens, not a pinhole. There are some big repro lenses on ebay, around what focal length do you think would be the minimum to cover this size?

Thanks everyone


PS the film I'm using is 14x17 chest X-ray film. Its a strange film, blue sensitive, emulsion on both sides, weird stuff like that, but, it is a film, you develop and fix it like anything else, and you can get it at less than $1/sheet,just letting people know in case there are any others like me who want to try ULF (ultra large format) but don't have ULF (ultra large funds) :)

Eric Woodbury
22-Jun-2004, 22:36
Try the film and make sure you like it before you build a camera around it. You may not like the halation (sp?). Is the film thick enough so that it won't drop when held vertical? What speed is it to visible light?

Jay DeFehr
23-Jun-2004, 02:17
Tadge, I like your moxie. I'm also building an unconventional 14x17 camera, and I plan to use the 28" element of my Turner/Reich Triple Convertible, which is in a shutter, will cover the format, is not huge and heavy, isn't expensive, and is useful for other formats as well. I'm interested in your X-ray film, can you provide a link to a source? My next question is; if they're selling 14x17 film, are they also selling 14x17 film holders? If so, how much $$?

John D Gerndt
23-Jun-2004, 06:27

A single element from a convertible is a good idea, these, loose from their partners, are often quite cheap (I believe you are going for cheap here, music to my ears). I can also recommend the Kodak 21&1/4 inch copying Ektar. It is not too large (exit pupil about 2 &3/4 inches) and sharp and cheap!

I too, wonder about the film you are going to use and its film holder. Have you visited any sites about building cameras? You can try http://janvanhove.com. My own attempt is explained there. I originally though about making a box/back for my 8x10 but structural rigidity dictated abandonment. I look forward to seeing your own solution to the problem.


Jim Galli
23-Jun-2004, 07:40
I have a little experience with the 1417 industrial Xray film that is used for structural Xray of machines. It comes in different "speeds" and much of it has emulsion on 2 sides which is a little different. So you could get an image on 2 planes 7 or 8 mils away from each other. That might give an intersting un-sharp type mask effect all in a single sheet. When I batch chems to process the stuff, I usually will grab a 4X5 neg of something I like and put it in the enlarger. I then treat the xray film exactly like a piece of enlarging paper and make a 14X17 positive. It acts more like paper than film. So for in-camera use with daylight my guess is about ASA 1 - 3 to start with. There are many different brands of industrial Xray film holders. Some are press fit and some are put together with screws. The ones with screws can be taken apart and the black phenolic stuff replaced with glass. That would give a nice flat cassette but not with a dark slide. They also make the best contact printer on earth with glass instead of opaque phenolic.

Tracy Storer
23-Jun-2004, 07:47
Tadge, Almost any lens you can find in the "normal" focal length (22" by measuring the diagonal) should cover. The question is "how cheap is cheap?" I have a couple that may work for you, contact me off this list. Xray film actually works, I used to buy it from Freestyle (they no longer seem to carry it) and used it in pinhole cameras, and I have used it a couple times in my 14x17 holders. (the Xray film I've used has rounded corners) For "real" work, I use Bergger BPF200. I also had dreams of finding cheap xray holders that would work, but my search didn't go so far. Even if you find some, they probably won't be cheap or lightight outside...I bit the bullet and bought S+Ss, which are pretty good. (I also have one fidelity holder for sale) I'm loving the 14x17 format, Tracy

Tadge Dryja
23-Jun-2004, 08:37
Ok... so I should be looking for 22" and up. Sounds good...

I have used the X-Ray film a little bit, I cut some down to 4x5 and tried it like that. I got mine from www.mountainxray.com, and it definetly is much faster than a paper, I haven't done any real testing yet but I exposed it at 400 and got a reasonable looking negative. Under magnification / enlargement, there were some slightly odd things about it that could be because of the very thick base or the double emulsion or the blue dyes in the film or something, but I was pretty surprised how much it looked like a normal film, and doubt that you would every be able to tell in a contact print.

As for a holder, I was probably just going to do a one-shot kind of thing. I should look in to the 14x17 x-ray casettes though, maybe one of those can be modified to have a dark slide or something. The "holders" for x-ray use are totally opaque to visible light though, so one of those unmodified wouldn't be too useful.

Well, I'll keep everyone updated. Thanks

25-Jun-2004, 10:41
For 14x17:

360mm Apo-Ronar 502mm Caltar Almost any lens with 20+ inch focal length

X-ray film is being dumped on to the market (Ebay, etc) becuase of the trend to digital imaging. 14x17 X-ray film should still be around for a long time.