Dark streaks on photos

I have noticed that on several rolls on 120 films I have developed there are these dark streaks (dark on photos, light on negatives). All these films have been shot on a recent trip to Serbia, and have been through airport x-ray twice, but it doesnt look like x-ray damage to me. I know this is not a problem with the camera (Yashicamat) either, because I also shot some color films in it, which dont have this problem. The streaks appear in light areas of the picture (like sky).
I think the problem is in my agitation. I use an old Russian-made developing tank which cannot be inverted or the chemicals would spill out. Twirling the reel is my way of agitation. I admit, on some of the first rolls my agitation was somewhat chaotic. But on later rolls I did it for about 7 seconds at the beginning of each minute. I tried slow twirls and fast twirls with no success. The various rolls were developed at different temperatures from 20C to 25C, with no difference in the streaks.
I have 5 more rolls to develop and im thinking about trying semi-stand developing instead (I had good results with that).

I attached a sample with the streaks visible in the sky and in the distant hills.


Matis

I think you found the problem.

Get a stainless steel tank and reel if you can.

If you need to keep using the Russian tank then the best way to agitate isn't to twirl but to rock the agitator back and forth quickly with a 1/4 turn here and there - you want a very random mixed-up flow of developer over the film during the agitation periods.

You don't mention the film and developer you are using - sometimes these can contribute to agitation artifacts.

99% of these problems are from improper agitation or insufficient agitation. When filling a tank, the wet/dry edge must start and proceed across the film quickly/uniformly , and without retreating. Tilting and pouring developer over a few wraps on the spiral all in one place violates this principle. Drop the loaded reel into a prefilled tank unless you have machine rotational agitation or a Patterson which fills bottom up through a funnel.

Agitation needs to be vigorous and RANDOM. Vigorous to be sure developer by products are removed frequently and random so you get all areas or the film done. A non random pattern will set up "dead spots" that do not get replenished.

Agitate 30/60 seconds on immersion, then every 30 or 60 sec.

Twisty rotation in a horizontal plane tends to get more agitation along edges compared to the center result being prints get light edges and dark centers.

Violate any of this at your own peril.

I am wondering how the streaks relate to the position of the film in the tank. If those are vertical streaks vis a vis the film orientation--that is, the way they appear in your scan; they remind me of what is called "bromide drag" (I think that is the term). Is it conceivable that the streaks are directly related to film type information on the edges of the film--i.e. outside the frame area? If so, it is POSSIBLE that developer exhausted in those dense areas is flowing downward, dragging development-retarding bromide along with it.
Mere speculation on my part. In any case, prior advice to give constant agitation for the first minutes makes sense. Then five seconds on each thirty seconds; rather than seven seconds on each minute.
Anyother approach, if you can work in the dark, is to leave the lid off the tank and pick the reel up and out; rotate and replace several times each agitation cycle.

Anscojohn said:

they remind me of what is called "bromide drag" (I think that is the term).

Click to expand...

It does look like a bit like bromide drag. The camera is a TLR, so the stripes of drag are in the long direction of the film - also the direction of rotation when the film was agitated by spinning. The dark areas do seem to have some (though not very good) correlation with the bright (heavily developed) areas of the village and the picnickers leading one to think either bromide drag or depleted developer. If the twirling was very smoothly done then the depleted/bromide laden developer would flow evenly along the surface of the film.

Nicholas Lindan said:

It does look like a bit like bromide drag. The camera is a TLR, so the stripes of drag are in the long direction of the film - also the direction of rotation when the film was agitated by spinning. The dark areas do seem to have some (though not very good) correlation with the bright (heavily developed) areas of the village and the picnickers leading one to think either bromide drag or depleted developer. If the twirling was very smoothly done then the depleted/bromide laden developer would flow evenly along the surface of the film.

Click to expand...

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Would not, then, OP's suggestion he might try "semi-stand" development compound a problem such as bromide drag?

Thanks for the replies everyone!
The film is neopan 400 and I'm developing it in Fomadon R09.
I'm going to try to close the hole in the tank lid somehow, so I could invert it.

TTBOMK, Fomadon R09 is a Rodinal clone but has given people problems in the past with some distinctly un-Rodinal behaviour.
You may want to try using a low dilution, like 1:25, and regular agitation.

I have had more agitation issues with 120 film than 35mm or sheet film, with Rodinal (with several different films). HC110, no problem, but with Rodinal, I have to do things just right to avoid edge surge, a close relative to bromide drag, I believe.
For 120 film and Rodinal, my agitation is inverted, swirled, and rolled, and much more vigorous than I would with 35mm, for 15 sec every 4 minutes. Any other scheme gave me surge problems.

I'd say Ron has this one figured out. Judging from my own experience working with students in the darkroom this sort of problem always has to do with agitation. I've used Agfa Rodinal (but never R09) for years for about %99 of the 120 film that I've developed and I've never had any problem like this when using inversion agitation, at any dilution or length of development. When the kids in the darkroom at work come in with those old GAF tanks that can't be inverted they often get negatives that have similar problems...

- Randy