What clouded my negatives?

I'm having a devil of a time with wavy, streaked areas on my 8x10 negatives. It happened on one negative with a nice sky darkened by a red filter. Some of the n icest shadow detail I've captured in bright sunlight. But I can look at the emul sion side and see streaks that run the length of the film. If the area is in the sky, it is visible. Sometimes it's not objectionable, but usually it is. In one shot, it showed up in an area that looked natural. Fortunately, it didn't happe n on 2 other negatives with big sky. Here's my darkroom routine: - HP5 shot at ASA 100 developed in Pyro PMK. One sheet of film per tray holding a liter of developer. - Strong agitation for 10-15 seconds every 30 seconds. - Water bath for 30 seconds. - T4 Photographer's Formulary fixer for 3 minutes. - 2 minutes in washing agent. - 20 minutes wash. - No photo flo. Air dry, which usually takes about 12 hours. I stopped using foto flo, thinking that was my problem. Now I may try skipping t he washing agent. If this is not a developing problem, maybe I can get rid of th e streaking by toning in selenium, but maybe that would make it worse. Any suggestions?

Bruce, i would first look at your development technique. I haven't had streaking for a while but a couple of things come to mind regarding agitation. For 8x10 in PMK I use an 11x14 tray. That reduces the developer waves from bouncing off the tray wall and clapping somewhere within the negative area. If the developer continues to clap within the same area throughout the entire development time then an uneven density may result. The other point would be to produce a random but consistent agitation technique such as lifting from opposite sides of the tray to produce the agitation. This prevents any swirling patterns from happening. I don't know if you have already been using these techniques. I hope this helps in some way.

Dave.

Dave, It's a bit hard to tell exactly what your streaks are without looking at them (i.e, deposits or density variations), but here are a few ideas for what they are worth. First, DO use photo-flo and mix it with distilled water. A final rinse in distilled water for at least 2 minutes will lessen the chance of streaks from hard water deposits, especially important if your water quality is not the best. Second, lift your neg out of the tray once a minute a turn it 180 degrees. Not only the turning, but the lifting out and resubmerging of the negative will help prevent uneven development from standing waves in the developer. (I, personally, have found tray rocking to be completely inadequate as an agitation method). Also, make sure you give your negative continuous agitation (lifting in and out and turning) for the first 30-60 seconds in the developer. Not doing this can cause uneven deelopment. If you are not already using a water pre- soak of at least one minute, do so and increase your development time by 30 seconds. When using pyro developers DO NOT use a washing agent. These contain sulfites which remove the pyro stain you are after (in your case, maybe unevenly??). You probably cannot save your already damaged negative by anything short of scanning and digital manipulation, if that, so concentrate on refining your procedure to eliminate the problem. These things can be maddening, so don't get discouraged. I once spent a week exposing about 70 rolls of 120 film under the enlarger and then developing them to find a similar streaking problem. Good luck!! ;^D)

Bruce,

I'm really sorry I missed your name on the first try. Must have read someone else's in the process of answering and stuck it in there by mistake. However, the answer for Dave applies to you as well ;-) Regards,

It definitely sounds like uneven agitation. The advice about using an 11x14 tray is good, and also using gentle agitation by lifting the tray at each edge, working your way around the tray.

I'd second the uneven agitation suggestion. PMK is notorious for streaking if the agitation is not vigorous enough. I would be inclined to try the smaller tray suggestions made in the previous posts. Although I don't use 10x8 (yet!) I also had problems with 5x4. I used a pre-soak in water to which I added a small amount of sodium metaborate. This, together with a more vigorous agitation method has "cured" the problem. Regards Paul

I use plastic trays that measure roughly 9x12, but they were cheap storage containers. I use vigorous agitation, really splashing the developer around and I try to be as random as possible. But maybe with a combination of a presoak, and using 11x14 trays, and distilled water with foto-flo, I could eliminate this problem. One question: would there be anything wrong with using my water bath to presoak and then use it as the stop before fixing in T4? I don't have a lot of sink space and that would be one way to save space.

If you are doing one sheet at a time you have a couple of things to try. Besure you have enough developer. At least 2 1/2 to 3 inches if possible. DON'T DON'T DON'T rock the tray. Lift the film out and slide it back in, by the end and by the side alternating the ends and sides. Emulsion up and emulsion down with constant agitation. USE GLOVES and see if the problem goes away.

I have not had a problem with PMK and damaged emulsion. I do 6 to 8 sheets and "shuffle" them like cards, alternating sides and ends with the emulsion down. Puling the bottom sheet out and putting it on the top using constant agitation.

Good luck, these probl;ems can be a bear to isolate!

Bruce, I would suggest you invest in a 8x10 unicolor drum and roller and give it a try. It works at slow speed and changes direction after each rotation. I have had nothing but great results with one for my 4x5. It is easy to load and you can work in the light. You will also use about one tenth the chemical. I have to assume you are developing for the time specified by the temperature of your developer. I would suggest you increase your fixer time to 4 minutes and definitely use photo flow. I also didn't see where you were putting the negative back into the pyro after the last fixer before washing. This is the most important step in using pyro to acheive the detail it can produce. I hope this helps you some. Doug

Bruce, Marv is correct in saying not to rock the trays. My streaking was gone once I moved to multiple sheet processing and I had to slide the film in and out of the developer.