[rollei_list] Re: was Rollei Retro Film now is Rodinal pin holes

On Feb 25, 2008, at 08:44, Richard Knoppow wrote:

>     Real pin holes are very rare. They are actual physical
> disruptions in the emulsion caused by gas formation. First
> of all mot films are hardened to the point where such
> disruptions would require very extreme conditions to form,
> if at all. Secondly, few film developers contain carbonates
> these days and its the effervescense of carbonate that
> caused the problem in the old days. Rodinal contains
> hydroxide which I don't think causes outgassing.
>     It is possible for apparent pin holes, that is clear
> spots, to form because of dirt on the film during
> development or because of small bubbles of air stuck to the
> surface. The last do not usually show up as pin holes but as
> "air bells" small clear areas with a dark surrounding.
> Jarring the film tank on the bench a couple of times after
> filling it usually knocks off any bubbles but they can
> survive normal agitation if not knocked off.
>     Pin holes can be the result of a coating problem. This
> happened to T-max films a couple of times and Ilford has had
> the problem but I have not heard of anything recently and
> its pretty rare.
>

Well, given those facts and given the fact that at least on this one 
roll of film I have tiny clear spots visible mostly in the sky.  About 
20 spots total.  I have to conclude that somehow I caused the pinholes. 
  They are way too small to be air bells and I never get air bells in my 
processing tank.  I think the dirt possibility is very unlikely as the 
pin holes are very tiny and seemingly uniform in size and I have never 
had a dirt problem and with fresh Rodinal and a fresh cleaned 
processing tank I just don't see it.  So I guess I am down to bad film 
coating at Fuji.  I hope not because I have over 200 rolls of the same 
emulsion.   The only other time I have seen pin holes exactly like 
these is when I tested out some 120 EDU film from Freestyle a couple of 
years ago.  I guess I will try a plain water stop bath and maybe a 
different colored pair of socks.  Seems like another of photography's 
unexplainable phenoms.

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