Re: washing sheet film

Judy Seigel (jseigel@panix.com)
Thu, 14 Mar 1996 02:23:59 -0500 (EST)

On Wed, 13 Mar 1996, Carson Graves x4692 3NE wrote:
> you need to do very little washing to get down to a trace amount of
> thiosulfate. If you use a washing aid, you literally don't have to do
> more than rinse the film off.
>
> washing period, you apply HT-2 solution to a clear area of the film
> emulsion, wait the requiste 2 minutes, and then use a densitometer to
> compare a double layer of the stained film with unstained film base
> plus fog. There is a table that you can use to relate the difference in
>
> It turned out that it was difficult to get any stain, literally
> requiring testing right out of the fix. If there was as much as a 1
> minute wash, or 2 minutes in a washing aid combined with a few seconds
> rinse, the stain wasn't measurable.

Thanks to all who answered. And thanks especially to Carson for the
really good news, the best news I've had this year.

The problem (now removed by this good news) was that the 30 by 40 cm (12
by 15 1/2 inch) film is very floppy, billows up like a sail, even with
weights on the corners, and rises to the top of a tray of still water in
short order. A drum (which I didn't think of) probably would do it, but
now no need to get the monster because the above brilliant, humane &
exciting report suggests that the film is washed in the time it takes to
float up. (That's lith film and N31p; heavier sheet film, like Tri-X,
doesn't give the same problem.)

Now I'm curious though, Carson -- were those tests on "regular" sheet
film, roll film, or just graphic arts films? When I think of all the time
I myself have spent washing roll film, plus all the expensive salthill and
kostiner high pressure rising and falling elaborate, complex, dedicated film
washers, well, the mind boggles.

> So, perhaps the answer is to not put so much effort into washing the
> film. It is likely that the negative is at greater risk from
> contamination during the printing process than from any potential
> residual fix.

There was a piece in the NY Times today debunking carbohydrates. Back to
protein (like steak!) for weight loss is the latest. So back to a dunk in
the river (or nearly) for film? But as to contaminating the negative
during printing, oh yes.

Judy