Fish - Macro Test - A Problem

With a 4 second exposure it could possibly be flickr from your light source. It looks like light a lighting issue to me.

Is it in the negative, or is it a scanning artifact? I've had some scanner issues with bands along one edge of the negative like that.

- Thomas

It's definitely in the negative. I've scanned shots from my Bronica and they are all clear.

ishutter,
It wasn't in the frame when I composed and the light seemed perfectly steady during exposure. I've also had this show up on shots taken at night of downtown London, Ontario lit by street lamps so it's probably not the lighting. I thought it could be a flap not open all the way for the full exposure but I don't know too much about the internal workings of my camera body(yet).

It could be an internal reflection off something in the bellows or the camera. I also notice you're getting vignetting in the corners, which is caused by the bellows at extreme extension.

Flying,
Yes the vignetting I expected was from the bellows and you may have something with regard to the reflection. I'm not quiet sure what to do about that though. I'll look into it some more and see if I can find other examples with the same issue.