Archived posting to the Leica Users Group, 2002/03/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Once and for all time-- Pinholes are bubbles that form IN the emulsion and burst through to the surface. They are usually caused by too strong an acid stopbath, reacting to the carbonate alkali in the developer. Bubbles that form on TOP of an emulsion and restrict access of the developer to the image are called Airbells. They are usually caused by a lack of agitation and surface tension of the film surface. The physical difference is that Pinhole bubble have ragged edges as oppose to smooth edges of Airbells , when viewed under a microscope. yours recalling a 1970's lab lesson, Garry D. Lewis - -- enlightenment is just a light socket and hairpin away....BUZZZIT. - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html