What causes large blank or opaque patches on film negatives after development?
Asked 9/5/2018
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I'm seeing irregular patches on my developed film negatives. Sometimes the patches are large, and some appear near the film edges. My fixer is fresh, so I'm trying to work out whether this is a camera problem or something that happened during processing. What usually causes this kind of defect, and can anything be done to salvage the negatives?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
7y ago
2 Answers
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When we develop film, we must take care that the film is properly wound on the developing spool. This is an example of improper loading of the spool. On the reel, the film is coiled so that it can be process using only a small light-tight tank. Improper windings allow the film to touch. Film in close contact will stick together. Once wet, the gelatin that coats both sides of the film sticks firmly preventing fluids from penetrating. You can attempt to mitigate by swishing the film in fixer. This will clear the opaque areas but likely the developer was unable to infuse thus those areas will be void of an image.
You need to sacrifice a roll or two, practicing loading the reel in the light and then again and again with your eyes closed. You can’t practice with a roll indefinitely as loading and unloading damages the natural curl of the film. In other words, you will need to sacrifice several rolls to truly get the hang of the loading procedure.
On another note: Once you finish the learning curve, save the film, it can be used to test the developer and fixer. Cut the films into snippets about 2 inches (50mm) long. You can swish one in a sauce cup of developer and in the light, watch it blacken. While not a perfect test of the developer, you will know that it is a developer and that it still has some life. You can also test the fixer to prove it’s alive. Swish a snippet in fixer and watch in the light as it changes from opaque to milky to clear. The correct fix time is always twice as long as it takes for the snippet to go transparent.
Originally by user44949. Source · Licensed CC BY-SA 4.0
user44949
7y ago
0
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These patches are most likely a processing issue, not a camera fault. The usual cause is film touching or overlapping on the developing reel, so developer and fixer could not reach those areas properly. This often creates large blank or opaque patches, including near the film edges.
If parts were not fixed, residual silver can remain in the emulsion. You can still re-fix the film: wet it, then run it through fixer, wash, wetting agent, and dry again. This may clear opaque unfixed areas, but any sections that never received developer will remain blank because no image was formed there.
To prevent this, practice loading the film smoothly onto the reel so it does not kink, overlap, or stick to itself. Many people rehearse with a sacrificial roll in daylight, then repeat by feel with eyes closed until loading is consistent.
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