Quote Originally Posted by Darkroom317 View Post
Update.

I started by cleaning the mouth of my bottle of Rodinal. Dried up Rodinal had coated this area. I also cleaned out the small beaker I measure it with. I often don't do this between films but I cleaning right after I mixed the developer with water. I also tapped the tank after the first 30 sec of development as well as before.

I then used water as stop instead of stop bath. I continued with the agitation time of 10 sec every minute but with far more vigorous agitation. So far all of these problems have resolved.

This has certainly made me more cautious when developing my film.
Good you got it worked out! The pre-rinse, and avoiding the acid stop bath seems to be strong contenders for the problems you've seen.
For what it's worth, most people saw problems with the Foma 200 film in 120 format, a few reports on the Foma 100, and I can't remember any complaints about the 400.

About agitation: The purpose of agitation is to bring fresh developer in contact with ALL of the film area in the tank, at the same time. If your agitation is too slow, then you run the risk of uneven developing, and if it's too fast, you could see edges of your negatives more developed than the center of the film.
A happy medium is best, where you need to make sure of the following:
1. Do NOT completely fill the tank, because if it's completely full, the developer will not flow inside the tank to properly mix the developer up before you set it to rest again.
2. Do full inversions, but do it fairly slowly, like one full inversion in about three seconds or so.
3. Do not shake the tank.
4. Tap the tank before you set it down to rid with air bubbles trapped on the film surface.

I had lots of problems with uneven development in 2008, and my actions above solved all of them.

Good luck!