Possibly another Uneven Developing question. Jobo and Obsidian Aqua

[steveo]

I've been developing my sheet film in a Jobo tank with a 2509n reel for 5x4 sheets and 80% of the time its fine. I switched from Rodinal to Obsidian Aqua which I'm liking and helps contain highlights in my city night shots but OA doesn't like rotary developing so I've been using using the big jobo as an inversion tank (This isn't a problem with OA as its fairly cheap.) I don't think its the developer in isolation as it works fine on 120 in a standard Paterson tank

My process (courtesy of Regular Rod) has been 13 minutes in the developer, invert 20-30 times for the first minute, then four inversions every two minutes. Initially I was being quite gentle but the last two batches I was more energetic. I also added a presoak to the last two batches but in both cases there was one sheet which had streaks. The sheets were in two different slots in the reel.


First and most obvious.
https://farm1.staticflickr.com/306/20272308126_fd0488a24c_b.jpgDevelopment problems? ('https://flic.kr/p/wToSVU') by Steven ('https://www.flickr.com/photos/49248828@N06/'), on Flickr


Secondly it's less obvious but in the highlights in the top right there is distinct mottling.
https://farm4.staticflickr.com/3801/20110538398_823447ebc0_b.jpgDevelopment problems? ('https://flic.kr/p/wD6LqE') by Steven ('https://www.flickr.com/photos/49248828@N06/'), on Flickr



Anything else I can try to my developing technique or is this a camera/film holder issue? Are these in fact two separate issues?

[Jim Noel]

The reels are not designed for inversion. I suspect the films are touching each other at times during the processing. I would try putting film in alternate slots only to see if it solves the problem.
It is too bad these very nice images are ruined.

[steveo]

The reels are not designed for inversion. I suspect the films are touching each other at times during the processing. I would try putting film in alternate slots only to see if it solves the problem.
It is too bad these very nice images are ruined.

Ah, good shout. Just checked my notes the top one was in one slot with another sheet in the adjacent slot, the second one had a slot gap. I wonder if loading the sheets back to back would help. Put the emulsion facing inwards on the inner slot, leave a gap and put the other sheets in the outer with the emulsion facing outwards.

Thanks Jim, I've got an undeveloped copy of the worst. I'll probably mess around in photoshop and try to rescue the other. Hopefully this will solve it.