I have been using 70mm Kodak Infrared Aerographic Film 2424 since 1987 in a Mamiya RB 67 70mm back using Kodak 70mm metal cassettes.

The film is available in 70mm x 150 ft (45.7 m) with 35mm perforation (Sp 494) as Cat. No. 169 0841 from any Professional Kodak Dealer (have them look in the Aerial film section of their Kodak ordering book). If you already have purchased the film you will note it comes in a metal container. Inside, a metal core with side flanges holds the film around a central metal core.

I have not found a bulk loader necessary, especially since the film MUST be loaded in total darkness, thus, I did not purchase the bulk loader, also because it was very expensive (don't remember just how much--that was back in 1988).

I keep the film frozen until the night before. I let it thaw overnight. Remove the film from the metal container and place it into a small, square box so it will not roll around. I have been loading HIE directly into the Kodak metal cassettes in TOTAL darkness (turn off all fluorescent lights at least 2-minutes prior to loading) directly off the metal spool onto which it is wound. ( The cassettes MUST also be rolled and loaded into the back in total darkness.)

Open one of the metal cassettes. Remove the plastic take-up spool and take off the metal clip. Insert the end of the IR film onto the plastic take-up spool, and fasten the film onto it with the metal clip. Slide the film-attached-to-spool into the metal cassette and snap the metal endcap firmly. You can check to insure that the cassette is closed by taking the film and gently pushing to and fro. If it slides back and forth inside the cassette easily, there is no binding. Just make sure you can feel the cassette end caps snugly against the raised ridge on the cassette.

You now have the film attached to the take up spool, the cassette closed. Notice that the end caps of the cassette have openings in them with a flange that projects toward the inside. It fits snugly into the opening of the take up spool and allows it to rotate as film is wound onto or pulled off.

You merely need to fashion some sort of crank that can be pushed into the opening of the take-up core. I cut a wooden dowel rod into a 4 inch length with a tapered end which fit snugly into the plastic end of the take-up spool. You then insert the dowel through the opening in the end of the cassette directly into the plastic take-up spool, which is inside the 70mm cassette. I placed a finishing nail 90-degrees to the axis of the dowel rod so I could "crank" film onto the take-up spool inside the cassette.
I place the bulk roll with the film going away from my chest. Holding the cassette in my left hand, I insert the crank into the cassette end and begin slowly turning. Turn the crank with your finger approximately 60 turns. This places about 55 exposures inside the cassette [nota bene: Mamiya holds 65 exposures; Hassleblad and others only 55]. You will lose approximately 3 frames at the front and 2 frames at the end, much as you would with bulk loaded 35mm film.

The major problems surrounding use of 70 mm format are those of incorrectly closing the 70mm cassette, which allows fogging to occur. The other area of concern is the felt light trap on the film back. Replace it every 3-4 years if you use the back heavily, as I do. If you purchase a used back, inspect the felt lining for signs of deterioration. It will cost about US$125 to replace the felt, but this is insignificant since the new backs are up around US$1,050.

I rate the film speed at EI 200 (daylight) with used with a Wratten 25 (red) filter over the camera lens. Using an 87C filter decreases the rated film speed to EI 64.

I process the film in TMAX-RS developer diluted straight from the concentrate (mix Parts A & B together into the original container). Dilute the concentrate 1:9 using deionized water to minimize pinholes. Develop for 8-minutes at 70F (for a cold-light head enlarger with variable contrast paper). I use a 70mm Kinderman reel and tank. I fill the tank with developer and drop the loaded reel directly into it. I use constant agitation for the first 15 seconds, then two inversions every 30 seconds. I remove the reel from the developer 15 seconds before the conclusion of developing and drain the reel. I then place it into either running water or a stop bath. Fix in a non-hardening rapid fixer (1:3) for not more than three minutes. Immerse in a washing aid and then wash in running water for ten minutes.

I purchased a Kinderman stainless steel reel, but I do not remember model number or anything else. It was expensive-- $80.00--back in 1989! I later acquired a used 70mm tank and reel from a colleague in Canada. Try a professional camera store in your locale, or you might contact one of the large mail order houses located around the country. Shutterbug might be a good place to check, also. It is a flea market publication just for photo equipment and supplies. Good place to start. I purchased my first back--new, but very old--from K&L in Atlanta, GA.

Q: >Is your developing tank one that is open requiring development in total darkness or is the 70mm tank that you have a daylight type?

Well, I am using a very old Kinderman daylight tank. It holds 2-L of developer, which I add first and then gently lower the reel, close the top and agitate as you would with any other tank; however, realizing it takes two hands to hold a whopper!! ;>). I have turned the lights on after loading without fogging the film. I do NOT recommend pouring in the developer after putting in the reel, because this causes uneven development due to the length of time necessary to pour in the developer.

Q: > I will need to find the reel and tank to do my own developing?

Another alternative to the Kinderman tank is to go down to you hardware store and purchase some plastic paint buckets. They are wide and are used to pour paint into from the can. They hold 5-qts which makes the processing of one roll expensive, and you must process in the dark. However, the buckets are inexpensive, far cheaper than the Kinderman...

Q: >I assume that when loading the cassettes that you can use as little film as you want (total number of exposures) so long as you do not exceed the maximum amount (approximately 4.7 meters/15 feet with the Hassleblad equipment). Does that present any problems that you would know about? <

I have processed as few as 15 exposures while running my initial tests. You will still have to mix the full complement of developer, however, since the reel requires the full volume of liquid.
Another advantage of the 70mm format is that you will be able to use the E-6 color infrared film as well.

Q: > know that I will need to wear some kind of glove protection so not to leave fingerprints on the sensitive IR film. Do you have any recommendations? Can you use the latex type glove normally used for developing prints in chemistry, or is it better to use some form of cotton-linen glove that hopefully is lint-free. Any thoughts??<

I do not use any latex gloves, because I discovered a coating of talcum powder inside! And cotton gloves do have lint. Instead, I wash my hands thoroughly with soap and dry them. The important issue here is oil or contaminants on the skin. Washing with soap and water is still mama's best way...

Q: >every inch of the film was fogged right out to the sprocket holes along the edge of the film. I did however capture the various images that I shot. In other words the film wasn't entirely black; just "fog" exposure, plus the images. I don't know whether the problem is the dark-slide, or the film back itself, the film cassettes or what.

Well, you can go back to square one and try and duplicate the problem, which has been caused by: (1) the entire roll of film is/has been fogged, (2) the room has a light leak, (3) the camera fogged the film [probably wouldn't have gotten the sprocket holes], (4) the JOBO fogged the film, or (5) the developer fogged the film.

1. Take out about 12" of film in a changing bag (eliminates the room as a problem). Load the reel in the changing bag and process in the JOBO. If there is fog on this roll, then the problem is not the room but could be: (1) the entire roll of film is/has been fogged, (2) the JOBO fogged the film, or (3) the developer fogged the film.
2. Try processing another piece of the film in the JOBO with a different developer--say HC110. If unexposed film, loaded in a changing bag comes out fogged, the you can conclude either #1 or #3, or 4, but not #5. You can next take about 6" of your film and go unload it someplace else- -not in YOUR darkroom. If the film is still fogged, then my suspicion is that the JOBO may be fogging it....or the entire roll MAY be fogged. I have never had a bad roll from Kodak, and I suspect it is very unlikely that is the cause. It could be, depending upon how you got the film. Was it fresh? Was it shipped on ice? did your film dealer keep it frozen after receiving it? Is the expiration date still current? Call Kodak with the batch number and check for problems.

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