I have been testing Pyrocat HD and MC over the last several months with 35, MF, and 4x5. The attached images show something that happens only on 120 film, probably more often than I notice, since it takes a flat gray area to see it. It has happened with HD and MC. Looks like telephone wires across the top of the image. See the long scaled up image for a closer look.
If you look closely, you can also see, in the upper left corner, an area of slightly weaker development in the sky.
This is a rollei neg, so this defect occurs at the top of the frame, close to the space between frames, not at the edge of the film.
The film is FP4. The developer was Pyrocat MC 1.5:1:100 at 72F. I use a single 120 reel Nikkor tank, with enough developer to cover the reel by 5-10cm, but leave enough room for the developer to move around (420cc). I presoak for 4 minutes, agitate for 2 minutes, and, on this particular test, with MC, developed for 18 minutes, agitating once again for 20 seconds at the 10 minute point, halfway between the end of the 2 minute agitation and the end. All agitation is a twisted inversion, slow roll of the wrist, then rolling in the sink left to right. Slow but steady movement.
Stop is a minute of running water, and TF4 fixer.
This happened at least once before, with Tri-x and HD.
My guess would be that there is something in the camera scratching the emulsion off your film. If it was the deveoper, it would do it with all formats, not just the 120. They are black lines on your prints/scans, therefore the emulsion is missing, allowing light to go thru to the print/scan.
Check the inside of the camera, the back and insert to see if you can locate a rough spot.
That looks like an agitation artifcact to me. For this type of agitation, basically semi-stand, I would recommend a weaker solution and longer development time, say 1.5:1:200, and increase development time by about 1.5X.
Thanks for the replies. I'll try a weaker cut as Sandy suggests.
If you are not already doing so I would suggest dropping the reels into the developer rather than pour the developer into the tank. Then began agitation immediately, and it should be very vigorous at the beginning and last for about 1.5 minutes. Any problems that begin early in the development stage will become worse as developoment progresses.
Originally Posted by George Collier