large dark bands on the side of my film

Question

all the photos I've developed at home have a portion of them darkened by a band that runs across the whole reel I'm mostly using fomapan with an hour long stand development(agitation at 30 minutes, rodinol at approximately 1-100 dilution, i make sure the water is always high enough to stand in the funnel) my camera has a leaf style shutter so its probably not shutter malfunction can anyone provide advice on how to prevent this its always on the right side too the only thing i can think of is it being caused by my film sitting too low in my tank

Answer 1

Those look like "tide marks" -- caused by slow filling of a tank when pouring in chemicals. The part of the film at the bottom in the tank gets started developing before the film above it is covered -- or the stop bath fails to fully cover the film, or the fixer does so (and leaves retained halide that reads as density in scanning or printing).

I'm not a fan of stand or semi-stand development, but these aren't the marks of some of the failures specific to that method such as bromide drag (Rodinal isn't prone to bromide drag anyway); that would result in (frame-horizontal) "light shadows" in the positive following from bright areas in the frame, and we don't see that. They're also not due to full-development failure to cover the film, as that would have resulted in much thinner underdeveloped areas with agitation only at filling and halfway through an hour development.

These are not light fogging, either, as that would tend to run crosswise in the frames if due to "fat roll" loose backing paper after unloading, or intrude from one or both edges if due to camera light leaks, or have distinctive patterns if due to a very bright frame leaking light into dimmer ones before and after past the frame gate. If fogging occurred during loading the film into developing reel, it would tend to cover the entire film evenly.

It's remotely possible this is due to a cracked lid in the developing tank allowing a tiny bit of light to scatter inside intermittently -- but that's unlikely to create this pattern of light and shadow with no sign of spokes from the film reel's structure.

Answer 2

The pattern on "9" is too conspicuous. It looks very much like a shade from the film start, the part to be threaded. I'd say that you messed up when spooling the film, either before putting it into the camera, or when spooling it for development.

Either has to be done in pitch dark. Either in a handling bag intended for that, or a darkroom that is completely closed from any light. I'll assume that your development drum itself is absolutely light-sealed.

You absolutely cannot use a darkroom light here: those are only for handling prints, not for handling negatives.