On Fri, 26 Jan 2001 02:56:54 -0500 Tim Victor (TimVictor@csi.com) wrote:
> They agreed with what
> Michael Wilkinson just said, that film manufacturers don't
> take presoaking into account and it has noticeable effects
> on development which are different for different types of
> film stocks.
>
> I'm concerned that with such a short development time, it
> will be difficult to keep the temperature of the actual film
> reasonably near the specification without a presoak, but
> that the presoak, by pre-swelling the emulsion, might alter
> the result anyway.
You are doing the right thing by pre-warming the tank in the water bath.
Although pre-soaking takes care of temperature concerns nicely, the emulsion
being swollen with water affects the rate at which developer is absorbed. To
endorse what Michael says, at best this will mean longer than standard dev
times which will have to be worked out by trial and error. At worst, the
diffusion rate through the layers will be slowed so some layers receive less or
more development, leading to possible casts or crossed-curve effects.
Pre-soak can be a useful technique in B&W as it can reduce the risks of uneven
dev or airbells, but there dev times are always trial and error anyhow.
Regards
Tony Sleep
- Online portfolio & exhibit; + film scanner info &
comparisons
