How do pinholes develop, and how can I prevent this occurring?

-- fw (finneganswake@altavista.net), December 31, 1999

Answers

You didn't mention which film format your experiencing pinhole's with. If your using sheet film, dust collecting on the film's surface prior to exposing causes "holes" I suspect this could be true with 35mm and medium format, i.e. dirt in camera housing.

Also too strong an acid bath will cause a reaction with certain developers, forming holes in the film. Try using plain water for your stop.

-- John Clark (john.e.clark@mindspring.com), December 31, 1999.

For many years I have used a water bath for a few seconds before the stop bath. This provides a smooth transition from the high alkalinity of the developer to the high acidity of the stop. I haven't had a pinhole since I adopted this procedure.

-- (edbuffaloe@unblinkingeye.com), January 03, 2000.

Several sources for pinholes:

1. Airbubbles form on the surface of the film when the developer is poured in. If this is the problem you can do a presoak with water before you put the developer in. This may require a slight increase in your development time. Or you can give the tank a few raps on the countertop after the developer is in so dislodge the bubbles. I do both.

2. Using an acid stop bath can cause developer dissolved in the emulsion to emit a gas, taking some of the emulsion with it. A weaker bath or just a water bath will solve the problem. I recommend water.

3. I actually had a few rolls of film in the 80's where it appeared that there was a manufacturing defect in the film.

That's about all I know on the subject.

-- Charlie (charlie_strack@sti.com), January 21, 2000.