January 4, 2015

densitometry

Inspired by a discussion on a german board I made a new test with the  Kodak Technical Pan in Caffenol-C-L, compared with older results of Rodinal. The film was exposed @ EI 25, developed in Caffenol-C-L with 0.1 g/l pot. bromide, 11 minutes 20°C, constant agitation for the first 30 seconds, then 3 turns every minute.

No presoak here. I recommend using destilled or demin. water, the thin emulsion is very sensitive for spots. Check if your fixer is clean! And make a clearing test, fix for double clearing time, not longer, you can overfix these films quite easy. Here I fixed for 1 minute total with my regular strength fixer. Development was perfectly even, so I guess there is no need at all to use pot. bromide and maybe get a little bit more speed. After development I made 3 intermediate rinses (tap water this time) with shaky agitation to reduce possible spots. The final rinse was again made with demin water and the film carefully wiped with a V-folded paper tissue.

As you can see, the real speed is like ISO 20, with both developers Rodinal and C-C-L. But the red Rodinal curve is more contrasty. The blue C-C-L curve is better suitable for wet prints. Quite a nice result for a film that is said to be very difficult to handle, isn't it?

On my walk to do the test shots I met 4 young photographers and they were eager models for the test. Thank you very much, guys. I exposed @ EI 25, short before dawn I shot with 1/30 and f/1.4.

Happy developings - Reinhold



 click on the pics to make them bigger




4 comments:

FiatluX - Optimistic Illusions said...

Wow, you have a densitometer? I wish I could be as thorough as you Reinhold, great work with the zones!

ps. funny how the focus in your pics always seem to be on the girls.. :) ;)

Best,
Bo

imagesfrugales said...

Hi Bo, my scanner is my densitometer. Vuescan can show the densities moving the mouse and pressing the control button. Scan as 8 bit grey and there you are.

At f/1.4 you have to decide where to put the focus on ;-)

Phil said...

I've always wondered, what effect does overfixing have? I've heard people mention to be careful not to overfix a few times. I vary my fixing times from 10 mins to 45mins, depending on whats on the telly and when they have their ad breaks and I don't think it's had any major effect that I can see...

imagesfrugales said...

45 minutes with regular strength fixer? I would never ever do that.

Those technical (micro) films have a very thin emulsion and can be overfixed. With 35 mm film I always(!) do a clearing test. It's no additional effort at all besides a small mug for the snippet from the film leader. It makes sure that do a proper fixing for archival purpose and not to overfix at the same time. And if the clearing time increases noticeable, you know it's time to mix new fixer.