marks in T Max developinggreenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
Occasionally when developing T Max film I end up with marks running across the film from sproket hole to sprocket hole. The marks are around the width of the sprocket holes and this area of the negative appears to be more developed then the rest of the negative. I use the two reel Paterson drum.
Any suggestions would be appreciated. I have heard that pre wetting may assist.
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-- Jim Wright (firstname.lastname@example.org), August 03, 1998
On occassion, I've encountered similar, puzzling markings on both Tri-X and Plus-X. The folks at the local camera and photography shop have suggested over-agitation during development as the possible culprit. Since then I have been a bit more conscientious about agitating, thus appearing to have corrected the problem.
Is there really a coorelation between over-agitation and streaking around the sprocket holes? Perhaps someone more learned can say.
-- Wes Sechler (email@example.com), August 03, 1998.
I don't know if over agitating would cause these marks, I would think maybe too little agitation might cause uneven development. I work in a photo lab and when I see marks as they have been described, they are what are known as stress marks. This is caused by rewinding film backwards into the canister, as the film kinks inside the canister it creates a stress mark that runs across the film from sprocket hole to sprocket hole. This may not be your problem or maybe it is....
-- Jeff White (firstname.lastname@example.org), August 03, 1998.
Improper agitation can indeed cause uneven development around the sprocket holes, but this is usually limited to smallish areas around the holes. If the marks go all the way across the film, I doubt that this is the cause. Stress marks are a possibility. Strictly, these look more like overexposure than overdevelopment.
What camera do you use? You might try running a waste film through the camera. Leave the back open, and watch the film as you wind on, and then rewind. The film should, of course, run smoothly, without wrinkling.
Another possibility is that the film is getting crinkled as you put it into the spirals. Does it easily slide in, or do you have to force the twisting motion? Again, you can put a waste film in a spiral, and watch it as it goes in.
What is your development technique? Short dev times, less than around 5 minutes, can cause uneven development.
The photos on your web site (nice pictures, by the way) don't seem to show the problem. Perhaps you could put an example up; it would help with diagnosis. Reply to this thread if/when you do this.
-- Alan Gibson (email@example.com), August 04, 1998.
Sounds like over-agitation. You're developing in a motorized drum? Roll films are not meant to agitated continuously. Develop in a SS tank, prewet, make sure your development time is at least 5 minutes, agitate gently for 5 seconds every 30 seconds, and see if your problem goes away.
-- Peter Hughes (firstname.lastname@example.org), September 20, 1998.