Hi,
I've got a weird artefact on a roll of Portra 400 120 I recently developed. On a single frame I have a yellow/purple streak running horizontally across. It's just one frame that's affected and I'm just trying to understand what happened and how to avoid this in the future. This was processed in a Paterson tank in Fuji Hunt C-41 chemicals. I have processed several rolls of 35mm and 120 film before and since without issues.
Could it be a light leak?
Sorry for the censored image, this picture wasn't meant to be shared online.
