Dougg said:
INSTRUCTIONS FOR USE
1. Immerse film in Diafine Solution A for at least 3 minutes, agitating very gently for the first 5 seconds and for 5 seconds at 1 minute intervals.
2. Drain, but do not rinse.
3. Immerse film in Diafine Solution B for at least 3 minutes, agitating very gently for the first 5 seconds and for 5 seconds at 1 minute intervals.
I just got home, read this, and went to my chemical box and pulled out my instructions. You are right! Mine reads just as yours does.
I am not sure now where I got the notion that the instructions said not to agitate. Somewhere, somehow, I picked up the idea and it has stuck with me - but I was certain that it said that one the box - mea culpa.
Let me just say that I don't invert (the tanks I use can't be inverted) and I don't agitate Diafine - I just tap to dislodge bubbles. The only times I've had trouble with Diafine:
1) I used a wet reel - and the water soaked into the emulsion in places, but not everywhere. Let to underdeveloped spots.
2) I agitated (and inverted, different tank) and got weird trails that I presumed were what people call 'bromide trails'.
When I considered what agitation was for - what the purpose was - I was convinced that no agitation was best. After all, the job of solution A is to get soaked into the emulsion, which is water-soluble and acts like a sponge. Why would agitation change this? Even if it made the solution absorb faster, so what? There is no greater absorbtion than the max it will hold, so I don't see what agitation gains you there.
When it comes to solution B, its job is to react with the solution A that has absorbed into the emulsion. It is a compensating developer, which means that highlights don't get blown out while shadows get even development - the main reason we are warned against using Diafine in low-constrast situations, because it can bring down the contrast even more and make the scene 'flat'. So moving around the developer does not give us anything extra - the solution B that touches solution A develops until solution A is exhausted - and then stops. Agitation of solution B would bring more / fresh solution B into contact with the emulsion - but that would only hasten the point at which solution A is all out of steam. Once it is gone, development stops. So again, I don't see what agitation gets you, except to finish the development faster - but you're waiting three minutes anyway, which would be sufficient for the development to end on its own without agitation.
If, like many of us, you give solution A and B both an extra minute or two (and why not), then you should always have full development.
I tried to find Acufine, Inc.'s website without luck. I did find their address / phone number in Chicago. I'll try to contact them on Monday if I'm able to and will report back what they tell me about agitation.
Best Regards,
Bill Mattocks