I have a IIIc that a recent batch of negatives came back questionable. I'm confident in my skills as a technician I can get this thing apart and do it right, but what specifically am I looking for to cause this? Probably half of them look exactly like this. I don't see any pinholes I put a bright flashlight under the camera and ran the shutter a few times and didn't see anything. The speeds sound about right, especially the slower 1 second and 1/2 seconds those sound spot right on. All of these were done on a 15mm f4.5 that does not move the RF arm inside the mount, I know on the Zorki-5 this can be a problem you're not supposed to dry-fire it without a lens or fire it with a lens that doesn't actuate that arm, is this a IIIc thing too?
This was done on 400 speed film and most of these appear to be in the higher speeds which would be 1/500, the indoor shots at slower speeds seemed fine. I know the uneven exposure has to do with the speed governor and one curtain moving faster than the other.
I know this thing needs a CLA now, what do I look for when I pop this open? It will be my first Leica but I have done many Soviet rangefinders based on it and came out well.