One hour, 1+100, agitation 5 secs every 12 minutes... my guess is thermal convection along the surface of the film, since the streaks align either with the sprocket holes (esp in this one) or on occasion there will be a dark stripe trailing-away from a highlight indicating that the developer was exhasted there and wasn't fogging the base as much as it was in other areas.
Maybe just pulling back to less than an hour will do the trick and avoid this fogging....
couple of additional questions...what was the total volume of Rodinal used? Seems like I found that I had to mix up at least enough volume to have a minimum of 10ml of conc. or the developer would tend to exhaust. 2nd, what was the temp of the dilute developer during processing vs the room temp (was tank metal or plastic?)
I had this kind of streaking with APX 100 roll film standing in Rodinal 1+100. I had to get the standing periods between single agitation inversions down to 20 minutes max to avoid it, and decided to standardize on 15 minutes to be safe. That was with 5ml Rodinal per roll if you want a datapoint for photomc's suggestion. I didn't try it with larger volumes and more concentrate.
My time with APX 100 and rodinal 1+100 was 20-22 minutes with 5ml per roll. Depending on the scene, I either agitated 3 inversions every five minutes or 2 inversions every other minute. Never had a problem.
I'd like to link the defects to the standing intervals.
I think you might get away with this development scheme with ei 400.
For 2400 I'd guess agitation for 5 seconds every fifth minute would give you most of the benefits of standing development while eliminating the bad stuff.
After thinking about it a little bit, for EI 2400, you could probably succeed with 15 minute intervals with 1+50. There is - to me - no significant difference between 1+100 and 1+ 50 when agitation is minimized, but you ought to have enough developer to remain active in the low densities.
Or, you could stay with 1+100 and add 50 ml of stock Xtol to let the ascorbate go superadditive with the P-HCL... which borders on witchcraft but does work.
I find some films more prone to streak than others. My best results have been Efke 25, Rodinal 1+150, agitate 1.5 min then stand for remainder of 30 min.
Mark
I was also suprised by the handling properties of efke, at least pl100 in 35mm. It is dry out here and trix curled up like leaves, attracts a lot of static and hard to handle. The efke dried straight.
I managed to do something similar the other day with rodinal.. I forgot to shake up the solution. I had streaks from the sprocket holes on a few of the frames.