Re: [Leica] B&W Film and agitation!

["Dan Post" <dwpost@email.msn.com>]

Christer-
You are absolutely right!
I was examining some negatives from my friend Bob's darkroom, and he said
that using the right temp, and time his negatives were too contrasty. I did
a check with the densitometer, and sure enough, they were.
Now, Bob is about as anal retentive when it comes to following instructions!
He is great to teach because he writes down everything and follows the
procedures to a "T"- He uses an lelectronic timer that is just short of the
cesium clock's accuracy, and a thermometer that reads out in tenths of a
degree, and his negatives were to contrasty!
Here, Bob, I told him, is where Kodak ( and other manufacturers) say 'these
are guidlines only!'
It of course turned out that when he agitated his film, it was if the radio
was playing "Shake It Up, Baby", and Bob is very enthusiastic.
He has since gotten a 'roller'- here- the variable of how often to shake
rattle and roll is eliminated, and all you need to do is adjust the time and
dilution for your needs. Here again, removing a variable that is hard to
controll goes a long way toward a better negative.
I know that some people can time their agitation naturally ( Like the two
musicians that developed the Kodachrome process, timing their process by
humming a piece of music) but if you are like me, can't carry a tune in a
bucket, and have no rythm whatsoever, the roller helps!
As for grain-
I have heard various things- that a high pH developer softenes the emulsion
and promotes 'clumping', as does a too long wet time, and/or too vigourous
agitation... Now, I don't have any particular insight on that variable, but
I certainly would like to hear some thoughts out there!
Dan
- ----- Original Message -----
From: Christer Almqvist <chris@almqvist.net>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Thursday, September 02, 1999 6:22 AM
Subject: Re: [Leica] B&W Film


> My agitation is following: first 30 seconds
> >continuously, and then one inversion per minute (if I know the whole film
> >was shot in low contrast situations, I do two inversions per minute). The
> >more you agitate the more grain you'll get.
> >
> >Jiri D.
>
> As you said, the more you agitate the more grain you'll get. But it is not
> only a question of how long or how often you agitate, but also how you
> agitate.
>
> Kodaks own instructions are interesting. For T-Max developer they say
> "agitate vigorously", and for Xtol they say "agitate gently". They have a
> reason for using different terminology.
>
> Try the following: lift the tank -gently-  a couple of inches, then
> -gently- turn it round its own axis, wait a second or two to let the
liquid
> settle in its new position, then -gently- turn it back round, (wait a
> second or two and repeat turning as you wish), and then -gently- set the
> tank down. It makes a difference to the grain if you do it this way or if
> you shake the tank like a bar tender.
>
> --
> christer almqvist
> eichenstrasse 57, d-20255 hamburg, fon +49-40-407111 fax +49-40-4908440
> 14 rue de la hauteur, f-50590 regnéville-sur-mer, fon+fax +33-233 45 35 58
>
>