Trouble with Type 55 P/Ngreenspun.com : LUSENET : Large format photography : One Thread
I taught myself to use a LF camera with Type 55P/N film, to get immediate feedback on my mistakes. Never had any trouble with it back then, but now am using it again and running into 2 problems:
1. When pulling the envelope back out with the lever still on "L" (eg, to expose the film), the envelope sticks. If I still persist in pulling, there will be a "ding" in the metal at the end of the film, and I will get a blank sheet (presumably from the film never having been properly engaged, and thus not exposed). This happens _a lot_, and I can only avoid it about half the time by flattening the metal edge on the envelope before insertion. Happened both on my old holder and on a brand new 545i! Polaroid tech support no help on this.
2. Negatives clear enough to see clearly, but some sticky residue remains on the central 50% or so. Tried brand new sulfite, as I thought my clearing solution was exhausted, but still no dice. Polaroid recommended gently abrading this residue off the wet negative: bad advice! I'm an eye surgeon, and I still couldn't get this stuff off without damaging the (notoriously soft) emulsion.
Have I just gotten a few bad batches of film, or what am I doing wrong? Funny that I used this film for quite some time and never encountered either of these problems before. Thanks for any suggestions.
-- Nathan Congdon (firstname.lastname@example.org), July 05, 1999
I can't help with the first problem; never had that happen to me yet.
As for your clearing in the sulfite problem, I have the same problem myself! I talked to Polaroid and they seemed concerned, but short of sending them my film for testing, they didn't have advice to offer that solved my problem. I was a little annoyed when the guy told me that Dr. Land personally invented the product and that since Ansel Adams was one of the beta testers, then the product necessarily must be a good one with no inherant problems. At least I know now that I'm not the only one who has the same problem!
When I clear these negatives, I always have to rub on the negs gently with my thumb while they are in the sulfite. It's better to get as much as you can off the neg while its in the sulfite. The emulsion is not nearly as soft as when in water. I found slightly better results when I mixed the sodium sulfite in deionized water instead of the tap water that was available.
After clearing in sulfite, I found that my results improved when I rinse in deionized or distilled water. I still have some negs that need gentle rubbing at this stage as well. Once in a while I wind up with damaged negatives, but I haven't figured out a better way to do this yet.
Remember that the negative is about a stop or so slower than the positive. In order to get a decent negative, you really need to overexpose the positive.
If I could, I wouldn't even bother with the type 55. However, with the scanning electron microscopic photography that I do, I really need to have the info from the positive to let me know if I had a specimen charging problem during the long exposures needed to capture the images on film.
Anybody else with a good answer? I've tried leaving in the sulfite longer, slightly warmer temp, tap water vs. deionized water....
-- Bill Riemenschneider (email@example.com), July 06, 1999.
I've used Type 55 film only once but for other Polaroid films you move the lever from "L" to "P" before pulling the film out for processing. I thought I did the same for Type 55 film on the one occasion when I used it but it's been a while so maybe my memory is wrong. In any event, are you sure you're supposed to leave the lever at "L" when you pull the film out? If so, this is different from all other Polaroid films with which I'm familiar. Brian
-- Brian Ellis (firstname.lastname@example.org), July 06, 1999.
I've developed a habit, when pulling the envelope to expose the film...of giving it a gentle, but decisive 'tug'..sort of a snap, which seems to prevent the problem you describe. I also feel for the 'pod'..the bump which contains the processing gel when the envelope is out. If I can feel it..I gently slide the envelope back in and give it a couple of pushes to engage the catch. I have noticed manufacturing variances from batch to batch. Polaroid used to have a policy of replacing screwed up film envelopes if returned to them or a dealer...but I haven't tried this recently
-- C MATTER (email@example.com), July 06, 1999.
Question? Is there a heat factor when you are shooting polaroid? Could excessive heat be causing the sticking if the emulsion? Pat
-- pat j. krentz (firstname.lastname@example.org), July 12, 1999.
I've been using the 55 for the negatives and found that if you run regular tap water over the negatives that the emulsion is easily removed. I found that I do not have to rub on the negatives. Once I have most of it off then I place it in the sulfite solution.
I also pull the packet out to process witht the lever in the P position. If I want to save it for processing later in the situation where it's too cold then you can remove it with the "blue" button on the 545i depressed. Hope this helps.
-- Cal Eng (email@example.com), December 04, 2000.