RPX 100 (120): Damaged batch

auckland · 2017-07-30T19:51:17+00:00

Guten Abend allerseits, ich habe in den letzten Monaten ein gutes Dutzend RPX 100 (in 120er Konfektionierung, von unserem Forumssponsor bezogen) belichtet u...

auckland

Good evening everyone, Over the last few months, I’ve conducted exposure and development on a good dozen rolls of RPX 100 (in 120 format, purchased from our forum sponsor). They all have the same problem: towards the end of the film, roughly over the length of the last three frames (in 6 x 4.5 format), there are sometimes one, usually two parallel stripes on the images (‘telephone lines’) running parallel to the film edge. One is about 3 mm from the film edge, the other about 7 mm (see attachment). You can see on the film strip that it is a tiny scratch on the emulsion side. The line is perfectly straight and was probably caused by movement of the film during winding, unwinding or tensioning. My initial suspicion (the camera) can be ruled out, as none of the other films I run through the Mamiya 645E have this problem. Furthermore, I couldn’t find anything in the camera that might be the cause. Another possibility: my developing process, but I’ve checked this – nothing touches the film at this point. As the damage appears in a very consistent pattern across all rolls, I’m starting to suspect: a production issue? A faulty batch? Unfortunately, I don’t have any fresh RPX 100 here anymore; otherwise, I’d sacrifice an unexposed roll and examine its emulsion. Has anyone else experienced the same phenomenon with RPX 100 roll film? Many thanks

Cloudy8

Hello, Unfortunately, I can’t say anything about the RPX 100, but I’ve had a similar-sounding problem with my Mamiya 645 1000s, which may have the same cause. In my case, these vertical scratches always appear on the last two frames of a roll of film. There are significantly more scratches than in your case, and they’re spread across the entire width of the frame. I first noticed the scratches on an RPX 400, but an HP5 was then affected in exactly the same way. I can therefore rule out a film manufacturing defect in my case. After the last roll of film, I took a close look at the film holder and the camera again: as far as I can see, the film holder only comes into contact with the backing paper and can therefore be ruled out as the cause. That leaves the two thin black metal rollers in the camera, above and below the viewfinder. In the gap beneath the lower roller, I spotted a microscopic crumb, presumably a remnant of the seals that have since been replaced. This crumb was located exactly at the position corresponding to the deepest scratch on the negative. I then thoroughly cleaned the entire interior of the camera, and the rollers in particular. Unfortunately, I haven’t had a chance to perform another exposure on a test film since then. Your 645E uses the same film cassettes, so the film feed is probably similar. Of course, that doesn’t explain why you only see the problem with RPX 400. Have you ever shot an HP5? It’s just as unclear to me why it always affects the last two (in your case three) frames. I speculate that towards the end of the film, more tension is exerted on the film and it is pressed harder or differently against the roller. This could also vary depending on the thickness of the film stock. As far as I know, RPX films are manufactured by Harman, just like the HP5, so they’re likely to have a similar base. As you already mentioned, the fact that the scratches run exactly vertically in the direction of transport suggests that it isn’t a fault with the loading or developing.

auckland

I’ve got an update: as the problem only occurs with the RPX100, but not with the 400TX or FP4+ I’ve developed myself, nor with the Portra 400 or slide films processed by the lab, I now assume that the scratches in question are down to a manufacturing fault. Frankly, I don’t really care: for the time being, I’ll simply stop buying RPX films and stick to the rest of the range. It’s just annoying because I shot and developed over 10 of them whilst on holiday. € I’m just surprised that no one else seems to be having similar problems with them.

grommi

I’m just surprised that no one else seems to be having similar problems with it.

Well, with all due respect, there aren’t that many users reading and posting here. A query or search on APUG – which is now called photrio.com (who on earth came up with that rubbish name?) – would probably be more productive. And Impex isn’t the manufacturer or distributor you’d reasonably expect to ask either.