Puzzle about problem of very dark negatives on parts of rolls.

[Premier]

Hello all,
I have a puzzle that I am trying to work out: I developed two rolls of film together in one tank, using Black White and green developer from Flic Films, according to their instructions, except that my developer solution was a few degrees higher than the recommended 68 degrees. Strangely, the first 9-10 or so frames of each roll look good, but after that, everything thing looks either way overexposed or overdeveloped, or both. Many of the shots from both rolls were outdoors on extremely cold days (less than 20 degrees farenheit), except the initial frames of both of the rolls. I am wondering if what looks like overexposed or overdeveloped film is due to the temperature of the camera, and a slowing down of shutter speed at the time of exposure, or is due to the temperature of the developer, and is due to overexposure.

The cameras that I took these on are both older cameras: a Kodak Retina 1a, and a Fed 2d. The film is Kentmere 400, 35mm. I developed in the JOBO 1520 tank.

I would upload iphone images of the negative sheets, but the files are too large, and there seems to be a prohibition against using digital content in this discussion area.

 

[250swb]

If the first frames from each camera are ok and the rest not I'd think at those temperatures the grease in the shutter/aperture blades was gradually stiffening after taking the camera out of the warm bag. I think maybe the problem with posting a photo may be you haven't made enough posts before and not anything else?

 

[Premier]

If the first frames from each camera are ok and the rest not I'd think at those temperatures the grease in the shutter/aperture blades was gradually stiffening after taking the camera out of the warm bag. I think maybe the problem with posting a photo may be you haven't made enough posts before and not anything else?

Thank you for the reply! You helped me with two puzzles!