Diafine in Rotary Processors

[bob fowler]

I've heard that Diafine isn't recommended in rotary processors (Jobo,

Unidrum, etc). As an experiment, I went ahead anyway and processed

some J&C Classic 200 5X7 sheets that I exposed at EI 400 in a

Unidrum. The overall negative density was very high, and aside from

the negatives being a bit flat (expected), the results weren't too

bad at all. The film is a bit grainier than when processed in

Microdol-X 1:3 (also expected), but the results were still quite

good. A test scan of one negative is <a

href="http://www.apug.org/gallery/showphoto.php?

photo=6518&sort=2&cat=500&page=1">here.</a><p>

My question: Would it help reduce the overall density if I diluted

either or both parts of the Diafine before processing when using in a

rotary tube? If so, does anyone have any dilution starting points I

can try?

[lwg]

If the negative is both dense and low contrast you can shoot it at a higher speed to reduce the density.

[profhlynnjones]

Hi Bob,

 

Here is why it doesn't work well if at all.

 

The solution A is un-activated developer that is soaked into the emulsion.

 

Solution B is activator only which acts on the soaked in developer. If you use drums (which I really like, most of the time except for this), it washes the developer out of the emulsion and so the only development you get is the first few seconds.

 

In essence, Diafine is D76 split from the developer in A, and the remainder of the stuff in B.

 

I think this one was invented by Dr. Harold Baumann.

 

Lynn