I still so not think that there's something wrong with the developing tank/procedural issue.. I developed the HP5 and FP4 in 2 different tanks and at 2 different places. One at my home and the other at a local college lab. Both tanks have been used very often and no one reported any light leaks issues.. But anyway, I think I will shoot another roll and send it in the lab and see what happens
I think it is a problem with how you are handling the film once it is exposed. As backing paper, spools and sealing tapes differ between types of film, it may be that your technique with the colour films doesn't result in problems, whereas with black and white films and that camera they do.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
But that doesn't happen with the color film? Both were loaded in broad daylight..
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OK you load film in both cases, using same changing bag or darkrrom. The film goes into the same magazines. You load the magazines into the same camera backs and expose in the same LF cameras. You unload the film using same changing bag or darkroom. The ONLY place there is a difference (that we can discern from your lack of description) is at the end of the workflow...A) the film goes into your tank and is immersed in your chemistry, or B) the film goes to the commercial color lab. The film comes out imperfect when it goes into your darkroom and comes out of the wash. If the sequence is identical for the first three steps, just where, OTHER THAN SOMEWHERE IN YOUR PROCESSING, do you THINK things are going awry?!
OK so you process B+W in two places, using two different tanks. If film streaked in both locations, that leaves out the tanks as issues.
Do you bring your own chemistry to both places?
Are your cameras really not the same?
Are your film holders really different types for color than for black-and-white film?
Is your B&W film higher ISO than your color film?
We are playing the game "What is different between these two pictures" but only you have all of the 'picture'. Based solely upon what you revealed to us, it is somewhere at the end of the flowchart...your processing.
Last edited by wiltw; 06-01-2014 at 03:27 AM. Click to view previous post history.
How tight does the camera back close with film loaded?
A. No play.
B. Just detectable, .001 inch or less.
C. Loosely, .001 inch to .003 inch play.
I do not think film type has anything to do with it. The reason you are seeing it on the B&W and not the color is the film speed.
ISO 125 is 1 1/3 stops more sensitive to light than ISO 50.
ISO 400 is 1 2/3 stops more sensitive to light than ISO 125 and 3 stops more sensitive to light than ISO 50.
What was the light level in EV?
Which film is your posted strip?
As others have asked How tightly is the exposed film wound as you take it out of the camera? If you put the ends of the spool between your thumb and index finger holding it tight enough to prevent the spool from turning and pull on the loose end of the backing paper how far will it pull out before becoming too tight to move and further?
I routinely use ISO 400 B&W film to test cameras for light leaks. The EI I expose it at has no relevance to any light leak that may be present and many that are very noticeable on ISO 400 film are barely detectable on ISO 100 film.
the colour was developed at a lab, the b/w at home. So something in the home developing would be by far the most likely answer. Not a procedural issue but a leak somewhere. Crack in the developing tank or tank top? A leak in your film changing tent?
As others indicated it is a film/spool flange issue.
I most certainly appears to be spool flange light leak. There is a reason that film companies warn to handle in subdued light. Care must be taken when loading and unloading older folding cameras that the film stays tightly wound on the spool, and maintains that after unloading until placed on developing reels.