Strange development marks near edge of frame

[john_s]

Could it be foaming of the developer, like air bells but tiny?

 

[lamerko]

Could it be that the camera is throwing off lube oil that sticks to the film and thus the chemistry can't penetrate fast enough?

 

[Nikanon]

Could it be foaming of the developer, like air bells but tiny?

I actually just thought about something like this. I went down in the darkroom to inspect what happens in the tank with the reel with some water in it, I did notice very small air bubbles if I sloshed the water around that would hang out under the top of the metal reel. I tested this theory by developing a roll of Foma 100 first putting the film so that the sky was on the bottom (if this occurs its most visible in the sky where there are more even lighter tones) and by hitting the tank a little harder when agitating. It seems I agitated too hard and I ended up getting uneven development from bottom to top of the frame, probably from the excessive vibrations of the tank. I however did not notice any of the marks on this roll. I will try it again tonight with a test roll of the same film and see If I can get even results without the marks. See below pictures for one good size air bubble I noticed trapped even after normal tapping of the tank to dislodge it

 

[koraks]

I went down in the darkroom to inspect what happens in the tank with the reel with some water in it, I did notice very small air bubbles if I sloshed the water around that would hang out under the top of the metal reel.

That's what I was getting at in #45.

I ended up getting uneven development from bottom to top of the frame, probably from the excessive vibrations of the tank.

I'm quite sure that's no what you were seeing. How frequently did you agitate and what was your agitation method?

 

[Nikanon]

That's what I was getting at in #45.



I'm quite sure that's no what you were seeing. How frequently did you agitate and what was your agitation method?

I agitate by inversion every 30 seconds, one inversion on the minute and two on the 30 second mark, with a bang on the bottom after each

 

[koraks]

OK, that will produce good evenness.

 

[Nikanon]

OK, that will produce good evenness.

I'm shooting a dummy roll I can develop again tonight where I will try to be smoother with the inversion so as not to produce bubbles, and firm but not excessive with the tapping of the tank to remove any. Funny how you can have to revisit the basics after doing this for about 18 years!