Speed increasing with 2-bath developers

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I exposed a roll of Ilford HP5+ exposed at ISO 200, 400, 800 then developed the entire roll in a 2-bath Diafine developer for 3 min in each bath. The 400 and the 800 appear slightly overexposed with good defination, but the 200 is obviously underexposed with increased contrst. Is this typical of 2-bath developers? How is the apparent speed increse achieved? Any try pushing to 1600 and beyond?

-- Don M (maldos@cox.net), May 06, 2002


Hmmmmm, how can the film that you exposed at EI 200 be underexposed compared to the two films you shot at EI 400 and 800? With a lower EI you expose the film MORE, you know.

-- Patric (jenspatricdahlen@hotmail.com), May 06, 2002.

Patic, you are right! I'm so used to using slide film..the negs are dark and therefore overexposed.

-- Don M (maldos@cox.net), May 06, 2002.

Sounds better. :-)

Emofin is said to increase the speed too, and it's also a two bath developer.

-- Patric (jenspatricdahlen@hotmail.com), May 06, 2002.

Emofin is good for up to a stop speed increase. I use it as my main developer but to be honest I havent seen too much of the compenstation effect. And the grain is very tight.

-- Russell Brooks (russell@ebrooks.org), May 07, 2002.

I use Diafine with TXP 4x5 @ 400 and love it. I do use cold light printing so try pulling a print and see what you think of each side by side. Two baths typically only process the highlights so far and are exhausted so there is no danger of blocked highlights and the shadows are teaming with detail. This being said, the contrast of the negative is usually just right for near straight prints. Diafine has higher acutance than Divided D76 but the DD76 is extremely fine grain so I have both in my darkroom for different situations... love them both. If you need to push with Diafine, it is ok at 1600 as stated on the box but you start to loose shadow detail. If you want to really push, Acufine works better than Diafine.

-- Scott Walton (walton@ll.mit.edu), May 07, 2002.

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