Out with my Pinhole camera today in the slate mining areas of North Wales. It was a bright day so I decided to load the camera with Ilford Pan F 120.
On my return home I thought I would process the images in Rodinal 1:50. It has been a couple of years since I had used Rodinal, and in the past I have always used stand development.
Shock horror when I saw the results:
Air bubbles along the top of the negatives! It’s been a long time since I had those. I assume that air bubbles had been trapped between the film edge and the edge of the reel. I had used my normal agitation method: slow continuous for first minute, then four inversions every minute thereafter, each agitation followed by a vigorous rap of the tank.
So perhaps I was agitating too vigorously, having just come from using PMK-Pyro for 6 months? (PMK requires vigorous agitation). Perhaps Rodinal is quite frothy compared to other developers? I don’t know. I will need to put a test film though Rodinal with more gentle inversions before risking any important film. What a pain!
Postscript 24 April 2019
- I ran a test film through Rodinal 1:50. This time I agitated for the first 30 seconds, rather than a minute, and then 3 gentle inversions every minute, rapping the tank hard on the table twice after each agitation cycle. Result?
Air-bells a-plenty. Grrrr!
I need to sort this. Possibilities?
- Change from plastic to metal spirals
- Stop agitation by moving to stand development
- Make agitation more gentle still
- Increase developer volume from 600mls to 700 mls (590 mls is recommended volume)
Plenty of people do a good job with plastic reels, so I will keep using them. Stand development produces too extreme acutance effects, so I’m not willing to do this. So I am going to plump for a combination of 3 and 4.
For resolution see my post ‘Film staining‘.