Re: Pin holes in my litho

Judy Seigel ()
Wed, 22 January 1997 1:28 PM

On Thu, 23 Jan 1997, Bill Agee wrote:
> >Because lith film is high contrast, the pinhole problem is greater. My
> >"cure" is to add 0.5 grams of PEG 4000 (polyethylene glycol 4000) per liter
> >of developer. This is a wetting agent that does not react with the
> >developer, and insures almost immediate wetting of the entire emulsion. This
> >lack of instantaneous wetting is ordinarily the major cause of the pinholes.

> An additional idea is to pre wet the film in a water bath. This is
> something I do for my infrared film which has a tendency to pin hole. It
> works quite nicely. Try one to two minutes of pre wet before putting the
> film in the developer. I understand that Ansel Adams was a proponant of
> this technique.

I've been trying to reconcile my own observations with what's coming up on
this thread. Here's a stab at it:

Some of my students get specks on lith film, others don't. All are using
the same film (freestyle lith) developer (Dektol) & stop bath (acetic
acid). The specks are clearly dust & when they REALLY swab down the
staging area, generally disappear, except of one case last fall when no
amount of wash and wipe was a cure, but she said her darkroom mate was an
incorrigible slob so we blamed that. I've not seen "pinholes" that I
recognized as such at all, tho I've read about them.... Is it possible
that the reason the pre-baths help is by washing the dust off before
development? nadeaul@mailserv.nbnet.nb.ca (That wouldn't affect the blobs made by dust sitting on the
film during exposure, of course.)

My impression, however, is that the phenomeon is independent of whether
the lith is developed as high contrast or con tone...

Judy

----------