Originally posted by womble I recently got some films back from the lab I usually use.
Does the lab hand process or machine process?
Clear areas on the negs that shouldnʻt be clear is a result of:
a) Defective emulsion from Kodak. Iʻve never seen that happen before with Kodak or Tri-X.
b) Lack of developer in those spots. Could be a bubble IF hand processed, but the shape of the mark is not like a bubble.
c) Fixer dropping on the emulsion before development. Highly unlikely, and if they were that sloppy, youʻd probably also see finger prints.
My best guess is that something internal to your camera, during that one exposure, fell onto the film and created a shadow. Iʻve seen this with insects in a camera or dust/foam bits, etc. When the film was advanced, the two offending bits rolled away with the film.
Look carefully inside your camera and see if there is anything in the light box that could be deteriorating. Itʻs only going to be something a few millimeters in diameter.