If you enumerate every possible development technique, you can find those who who will counsel against using all of them.
Originally Posted by Arkasha
The only truly useful recommendations are those derived from your own personal experience, not that of others.
Everybody is different. One of the greatest areas of divergence is in development, specifically equipment and technique.
You need to learn to use a technique, assessing its strengths and weaknesses in your particular situation, before you badmouth it.
Yes, you can do a single roll in a two-roll tank. I would put the empty reel on top, just to keep things from bouncing around.
Originally Posted by newcan1
The air space should pose no problem. You only need enough chemistry to cover the roll being developed.
Agitate gently since the low volume of liquid will cause much more turbulence than normal.
For inversion agitation with one roll in a two roll tank it's preferable to include an empty reel to take up the extra space. Otherwise the reel with the film is sliding back and forth and possibly causing surge marks at the sprocket holes. Perhaps a bigger issue for stainless reels vs plastic. It's also a good idea to fill the tank to capacity even for one roll, also to limit excessive surging. The extra air if you don't should not cause any issue though, consider that for rotary processing, a tank that can hold as much as a liter upright might be used with only 3 or 4 ounces on its side rotating.
Agitation is one of those things that is very sensitive to individual technique, and what works well for some people doesn't work at all for others. The real answer to problems caused by agitation is to change what you're doing, and see if that helps, if not, try something else. Once you find success, do that every time. What I outlined above works for me, ymmv.
FWIW, the twirling sticks work, but the swirling should be gentle and slow and in alternating directions.
Do what you like.
It is possible to get even development with plastic tanks. I had the same problem with uneven development at the edges of the film you describe. It was even worse with 120 film. It was clear I wasn't getting the same agitation at the center of the film. I went to sliding the tank back and forth on the table top for 10 seconds each minute. I slid it as hard as possible, just to the point where developer is almost shoshing out the pour holes. This worked, but I went to stainless tanks and inversion agitation anyway, and no more problems. Enjoy perfecting your own method.