DIAFINE.. again (contamination issue)

[enrico__]

Hi, me again..

ok, i may be a little overly cautious but i dont want to stuff it up

completely and from previous posts and research diafine seems like

its pretty easy stuff to use. but..

 

my instructions say:

 

1: Pour Solution A into tank etc etc, (then obviously return to

bottle)

2: Drain the tank but DO NOT RINSE

3: Pour Solution B into tank etc.. (then return to bottle..)

 

Then in caps it says: PREVENT ANY AMOUNT OF SOLUTION B FROM ENTERING

SOLUTION A.

 

Of the responses and posts ive read some do rinse in between baths,

some dont. It doesnt bother me if I do or I dont but if I dont then

wouldnt traces of Solution A remain in the tank and therefore become

present in Solution B...??

 

Is this a problem?

 

Also can I process sheet film with this stuff? - I just realised my

box says 'roll films'...

 

(and I swear, I will get in the d'room and process the film before I

post again..:o)

[scott_walton2]

Yes and that is fine if A goes into B... it's B going into A that you want to avoid.

I use Diafine ALOT with alot of films both sheet and rolls and love the stuff.

Mostly, I use the older, non t-grained stuff, with sheets at speed (ie 400 ASA

for 400 sheet film and the like). I print cold light so it really works well for me!

[Troll]

Don't rinse between A and B! It's okay to rinse with either water or stop between B and the Fixer baths. Sheet film works just fine in Diafine, but the EI ratings given on the box may not be correct.

[david_karp]

I have used Diafine with HP5+ sheet film. For me, the EI on the box is optimistic. I shoot HP5+ or Arista 400 at 200 when using Diafine.

 

Don't rinse between baths. The A bath has the developer in it, which is absorbed into the emulsion. Little or no development takes place in the A bath. The B bath is the activator. If you rinse between the two baths, the developer will become dilute and you will most likely not have full development.

 

There is a helpful information sheet on Diafine at www.bkaphoto.com.

 

Diafine works great in normal and contrasty situations. It can be problematic in very low contrast situations. You can't do + development to raise the contrast.

[lex_jenkins]

Don't worry about Part A getting into Part B, Enrico - it won't hurt Part B. It's unavoidable that a few drops of Part A will get into Part B with every development cycle.

 

BTW, I recently checked on what occurs during the Part A cycle using a test strip of Tri-X. Virtually *no* development occurs if only Part A is used - you get clear film, tho' one heavily overexposed sliver on a tiny section of the test strip showed the barest perceptible bit of density.

 

So any real development occurs in Part B. It appears that some residual Part A *must* be present in the emulsion for proper development to take place. That's why the manufacturer instructs against rinsing between Parts A and B. Rinsing would remove the residual Part A (depending on how much rinsing was done) and no development, or uneven, mottled development would occur.

 

I think at least one person on this forum has speculated that if we mixed Parts A and B we'd get...Acufine! No way of knowing without experimenting but after I buy another batch of Diafine I'll test this theory.

[andrew_hull]

Having shot a lot lately and using Diafine, I am wondering how it compared with the other two-bath developers out there...AB-55 from Cachet and Divided D-76 from Photo Formulary, anyone have nay experience?

[lex_jenkins]

Regarding the theory that mixing Diafine Parts A and B will yield Acufine, there's a hint in the posted MSDSs, tho' an MSDS seldom reveals any trade secrets.

 

In the MSDS for Diafine Part A the only hazardous material listed is hydroquinone. For Part B the only hazardous material listed is sodium carbonate.

 

For Acufine the listed hazardous materials are both hydroquinone and sodium carbonate.

 

Of course this doesn't even mention the non-hazardous but active materials. And differences in amounts of ingredients can alter activity considerably even if Diafine and Acufine contained essentially the same ingredients.

 

At any rate, I doubt that mixing Diafine Parts A and B willy nilly would kill the chemistry or make it totally inert. It just wouldn't be Diafine any more.