Film Developing faults.

The most common faults that crop up in the course of processing a film.

• Spots on the negative indicate two things: there was dust on the film at the time of exposure and/or fairly large round spots on the negative indicate that air bubbles were trapped against the film during the process and suggests insufficient agitation. This can be avoided by agitating for thirty seconds at the beginning of development and by tapping the tank on the bench. (some developers require longer agitation). It must be stressed that too vigious and lengthy agitation can induce the same problem. A way of helping to reduce air bubbles is to use a pre-soak. Some developers like PMK Pyro and Rollie's R3 require a pre soak as standard.
• Black crescent-shaped kinks and clear patches more common with roll film but can happen with 35 mm cassettes, this happens where the film has been forced into the spiral making the film kink and touching the film beside it.
• Lines are most commonly caused by the film running across a small piece of grit on the cassette opening. It can also happen by over tightening the film in the cassette and bad handling. One of the most common, which has happened to me, is the use of a squeegee to dry the film. I have not used one since.
• Finger marks on negatives are caused by handling the film with wet, dirty and contaminated fingers. This can be eliminated by using disposable gloves during the wet process and cloth cloves when handling dry negatives.
• White marks are caused by grease and fixer before development and dark marks by fingers covered in water or developer. Slight damage can be retouched.
• Reversal of negative image is due in part or total to solarization making the negative into a positive; this happens when light gets to the unprocessed film during development. Care must be taken with the processing tank that the lid is fully secure before inverting.
• Uneven image density is a sign that there is not enough developer in the tank or lack of agitation. A low-level of developer in the tank will show as a dark unprocessed line along the top edge of the film.
• Reticulation is a lot of fine cracks in the emulsion this is caused by washing in too high a temperature or solutions greatly different in temperature. This can be avoided by making sure that the solutions only have a few degrees difference between them.
• Deposits on the negative and discolouration. Hard water may cause a chalky deposit on the negative that cannot be washed away in water. It can be treated with a two percent solution of acetic acid, then washed in clean water. The same sort of problem may be due to the fix losing its acidity. A treatment would be to harden the negative in one percent solution of formalin, then wash in sodium carbonate followed by water. Yellow-white negatives may be due to deposits of sulphur from a decomposing fixer, it can be remedied by hardening in a one percent formalin solution and washing in a ten percent sulphite solution at thirty-eight degrees.