[Leica] development questions

[Erwin Puts <imxputs@knoware.nl>]

>My questions are:

>- -1 Do I really need to overexpose a film to get the best result? (e.g.
>TMax 100, shot at
 >   64 ISO)
>- -2 Which film gives the current Leica lenses the credit they deserve?
> --3 Which chemical (e.g. Xtol, Rodinal, Tmax) gives the best result with
>that winning film?
>- -4 Do you dilute the chemical and if so, do you also store the dilution
>or only the concentration.
>- -5 In what kind of thing (glas or plastic) do you store the (diluted)
>chemical and for how long?
- -> -6 How much do I need of this (diluted) chemical for a Jobo UniTank 470
>ml (2 films processed simultaniously)
>- -7 What temperature do you recommend?
>- -8 Is there anything else to think about?

My answers are as follows. I will also react to some respondents.

1.Slight underexposure is best for  acutance and therefore best detail
resolution. Slight overexposure and subsequent slight underdevelopment is
best for shadow details and MIGHT be be best for tonal scale.
The balance between these variables everyone must decide for herself.
Obviously I use both approaches depending on the task at hand.
For D100 and Tmax I would start with EI80.

2. My winning films are Ilford PanF and Agfa APX25. Both are developed in
Paterson FX39, the best Beutler derivation on the market. So please forget
about the original Beutler: it is good for acutance, but bad for tonal
range.
For some purposes the TechPan (again developed in FX39) is superior. Only
problem with this film: high red sensitivity that distorts grey values. You
absolutely need a CC40 to get natural looking results. Apart from that a
fabulous film: I showed a friend some TechPan prints and he asked me in
utter despiration if I had abandoned Leica and started to use large format
negs!
Best films for Leica: PanF, APX25, D100, TechPan, Tmax100,  and the very
new Fuji 32ISO film (a revival of Panatomix-X), in approximately this
order.
3.Best developer by a very large margin: Paterson FX39 and  close to this
one: XTOL. Forget about the others. WHY. Modern emulsions are specifically
designed to be relatively unsensitive to developer actions. So the basic
image quality is produced into the film chemistry. The developer hardly can
enhance or detract from that inherent quality. Obviously a really fine
grain developer as Microdol or a hard grain developer like Rodinal will
define the extremes. For balanced results stick to FX39 or XTOL.
4.Always dilute and use once.
5. I do not store diluted chemicals.
6. For Jobo use 500ml per 2 films.
7. Not relevant: use 20 degrees as a start
8. Fine tune exposure and development times to a very narrow limit.

Erwin