Jan Tieghem wrote:
UC,

in another post you branded the Paterson times as useless. I have to admit
you're right.

Of course I'm right. I wriote to them repeatedly, asking for
justification for these times, and they simply pleaded that they could
not possibly be mistaken.

Typical British arrogance.


I developped Neopan 400 in FX-39 according to their instructions and it came
out much too dense and hard, although the film speed looks OK (frame with 5
stops underexposure has visible density).

WHY did you do that? WHY did I take all the trouble I did, to do the
reaearch on these films, and get them published on the digital truth
site?

As I'm using a diffusor enlarger, I'd rather not copy your suggestions - as
you tested for condensor printing - but try to fiigure out what I need in my
particular case.

Simply take what I say and add about 15% to start with. DO NOT change
the dilutions I recommend, only the times. It's much simpler that way,
and any errors in time will be less influential. That is, a 10-second
error at 10 minutes is less influential than a 10-second error at 5
minutes.

Use these dilutions, and add 15% to the times, to start with:

http://www.digitaltruth.com/chart/sc...-paterson.html

Follow the recommended dilutions EXACTLY! If it says 1+16.5, do it! If
it says 1+14, do it! I spent lots of money and time working these out.
You learned the hard way that Paterson's times were wrong (so did I),
now, TRUST ME!


Now I'd like to change one of the following parameters: dilution or time.

TIME!

But wich to chose?

TIME!

We know that higher dillutions and shorter time will both
decrease contrast. We know that the side-effect of changing development time
results in a slight change in acutal film speed. But what about the
relationship between dillution and film speed?

TIME!


In other words: suppose I want to decrease contrast in the same degree. What
would be the difference in film speed between both methods - shorter time vs
higher dillution?

Don't worry about it. The development time scarcely affects the real
speed. The effect is less than 1/2 stop.


TIA!

Jan

schreef in bericht
ink.net...
| I havn't developed my own black and white films for years.
|
| Would appreciate advice on best current developers for 35mm
| Neopan 400 . Been shooting sunny snow scenes with shadows.
|
| Ed Bcck
|
|