Camera leaks IR -- stopgap fixes?greenspun.com : LUSENET : Large format photography : One Thread
Well, after a good deal of experimentation, I've accepted that my camera isn't reliably IR proof, and it's probably the bellows (I've eliminated the back, filmholders, etc.). Annoying, as I've got some sheets of the film left that aren't going to survive until I can afford a camera that is. The main symptom I get is a serious overall fog effect which only extends into the border area from halation (i.e., fuzzy border edges).
If anyone knows anything in particular about the camera or lens pertaining to this, the camera is an old Calumet rail with no serial # or model # I can find, steel standards, synthetic bellows, which I've also seen badged as an "Orbit" (B&J?). The lens is a Sironar-N 150mm MC. Condition of both is nigh-mint and I have no problems with slides or B&W with it otherwise.
My question: is there anything I can do to temporarily IR-proof the bellows? I'm thinking of setting up the camera, composing, wrapping the bellows and front standard in tin foil, inserting the holder, removing the darkslide, wrapping the back standard in tin foil, and then exposing the film. Ideas?
Ancillary question: what cameras have you used that are or not IR proof? I'm specifically interested in cameras I might conceivably be able to afford: Graphics? used recent Calumet monorails (NX, Cadet)? cheap used Toyo rails?
-- John O'Connell (email@example.com), August 04, 1999
Very interesting! I use to own a B&J Orbit that behaved the same way. Like you I ran many test. I finally determined it was coming from a light leak in the rotating back. Never did resolve the problem. I just sold the camera. I have owned 5 other 4X5 view cameras since then and I have never had another problem like this.
-- R. Lawrence (firstname.lastname@example.org), August 04, 1999.
number 1 problem is probably the bellows aren't IR proof. second problem is shooting the IR. what is your normal fstop and exposure time? long exposures almost garrantee overall fog on 4x5 film. also how do you handle the film holder when using it. it should always be covered to the max extent possible. under your shirt, hand over the light trap under the dark cloth when inserting it into the back. no overheating. check your belows by shielding
-- james (email@example.com), August 05, 1999.
I had a major malfunction in the facility I am in charge of and not enough people to handle it so sorry for the abrupt exit. Anyway, check your belows by shielding the film holder all the way to the camera back and then without tripping the shutter, pull the darkslide. Leave it out for 30 secs or so and then replace it and take the holder out and without taking it from under the darkcloth, wrap it up and go process it. If it is fogged then you have bellows that are not IR safe. If it isn't fogged you have an exposure problem or a major leak in the back. Sheet IR is different from roll IR. It is a different animal. Make sure you are loading the holders in "absolute" darkness. Let us know how it goes. James
-- james (firstname.lastname@example.org), August 05, 1999.
Another thought: Does the fog seem to be most apparent on the side of the film where the dark slide is inserted/removed? IR film is so sensitive that if you completely remove the dark slide from the holder when making an exposure, a good chance exists that the edge of the film will fog due to stray light entering through the top of the holder. If this is the case, don't completely remove the dark slide; just pull it out far enough to make the exposure.
-- Chad Jarvis (email@example.com), August 05, 1999.
With respect to an inexpensive IR-proof camera, I did a fair amount of IR work with my Tachihara and had no light leak problems. The Tachihara costs around $550. With respect to the problem with your existing camera,have you tested to see if you have a light leak? If your problem is simply that the bellows construction/material isn't sufficiently light proof for infrared film then of course you would have to try the aliminum foil or some similar method. However, if could be that you just have one or two small pin hole leaks that haven't presented a problem with normal film but that create a problem with infrared because of its greater sensitivity to light and/or because you've been using longer than normal exposures with your infrared film.
-- Brian Ellis (firstname.lastname@example.org), August 05, 1999.
Thanks, folks -- I've tested the film holders I use and my loading technique for fogging and unfortunately they appear to be fine. I've tested the holders in direct sunlight and direct tungesten and they don't exhibit fogging (new Riteway and Fidelity holders). While I'm loading IR holders into the camera, I keep the darkcloth (double layer) over the back and leave it there until the holder is out of the camera again. The holders themselves stay wrapped in tin foil before and after exposure (even though leaks are not indicated by testing).
Indications would be A) I bought the only camera people have ever had trouble with, B) the bellows are not IR proof, and/or C) I need to try shorter exposures, as all of mine have been 1/4 second and slower. Pinhole leaks are possible, but 90 second exposures on Tech Pan (another easily fogged film) have not been a problem.
Next tests will be with flash and in sunlight at infinity focus, both tin foiling the camera. I have about 4 or 6 sheets left, so...
Thanks for the info on the Tachihara. Anybody use this film successfully on a Graphic?
-- John O'Connell (email@example.com), August 05, 1999.
Yeah John, I shot it alot with a beautiful Crown PaceMaker Graphic (wish I still had it). Your e-mail address makes me think you're in a foreign land (from me), but I put a brand new bellows on my Tech III for about $100 American from the Universal Bellows Company, 25 Hanse Avenue, Fremont New York USA, 11520. Phone # 516.378.1264.
They did my 8x10 Deardorf for $125, better than buying a new camera and the Linhof works great with Infrared...t
-- tom meyer (firstname.lastname@example.org), August 05, 1999.
The synthetic bellows might be the culprit. Some plastic materials are not IR proof. Have you tried to cover your camera with your dark cloth, all the way up to the lens standard? I have read that suggestion some- where, so don't blame me. As to my experience - I have been using a Wista DX with Kodak IR film, and I felt that there weren't any problems.
-- Ralph Peteranderl (email@example.com), August 13, 1999.
I run an older B&J Orbit with a red bellows. As I shoot a lot of IR your problems intrege me. My bellows is IR safe. Most of my problems occured if I took the dark slide all the way out. This is definetly a no no. Don't have the sun directly overhead and pull the dark slide up for exposure, orient the camera so you can pull it down. Several other areas a concern for IR film: 1)Storage temp - heat will fog IR! (I keep mine is a small cooler when in the field. IR lives in the freezer when it's at home.) 2)Exposure time - the shorter the better. 3)Develope the film as soon as possible after the exposure if possible. 4)Test your darkroom - the fogging maybe occuring their and not in the field. I have successfully exposed IR in Death Valley and have had no problems. I have been shooting IR in my F3-hp, F4, Widelux F7, Zone VI 4x5 and B&J Orbit (currently collecting lots of dust) or about 6 years now. Now if Kodak would only make for my 8x10 I would be in heaven. If you have any other questions please feel free to ask.
-- Scott A. Overby (Hawkinwa@aol.com), August 19, 1999.