Diafine: Help please for uneven development

[Ken Lee]

Was it too dim in there to take an incident reading in the shadows?

I'll have to try that going forward.

[Kevin J. Kolosky]

Ken

quote(Even though that old Tessar opens to f/4.5, it was very difficult to focus and compose under the dark cloth.)quote

Nevertheless, it looks to be well worth it. That "old" uncoated Tessar produces a very lovely "look". For lack of a better word it looks very smooth. I am sure you went through all of the tests for the film and developer. I would be interested to also know what film speed you came up with for TMY using Diafine.

[rdenney]

Hi Rick!

Sorry to hear you've become a moderator here, but that's another subject.

I'm aware that lower than needed contrast is more malleable than higher than needed contrast, but that has nothing to do with my comments. Ken stated that he added contrast to his test image for presentation in this thread, and the image in question looks very much like the larger body of his work. It's reasonable to assume the image looks just as Ken wishes it to look, and not that it is simply raw material for some other interpretation. It's further reasonable to conclude that Ken enjoys seeking out very high SBR scenes and shoe horning them onto film by various processing techniques. I simply question whether this exercise is a means to an end, or an end in itself. If rendering a sunny day as an overcast one is Ken's intention, his methods are very effective, but why would he want to do that, except as an example of that particular technique? I know many here have expressed admiration for Ken's work, and I mean no disrespect, but I don't share that admiration, which is not to say that I'm right, and they're wrong, just that I don't share their opinion.

Jay, the point I'm making is that Ken's work is his work, and has nothing to do with the subject of this thread. You bringing up your disadmiration of his work, however respectfully, isn't really relevant. It's like me writing a requirements document for a project that is traceably related to what I intend to do with the product of that project, and then having someone who doesn't like those requirements tell me I don't really need them, instead of telling me how I can fulfill them.

As to my becoming a moderator, no apologies are necessary. (That was a joke, you can laugh.) Pity, maybe. (That was also a joke, though not quite as funny, perhaps.)

Rick "respectfully submitted" Denney

[Ken Lee]

Ken

quote(Even though that old Tessar opens to f/4.5, it was very difficult to focus and compose under the dark cloth.)quote

Nevertheless, it looks to be well worth it. That "old" uncoated Tessar produces a very lovely "look". For lack of a better word it looks very smooth. I am sure you went through all of the tests for the film and developer. I would be interested to also know what film speed you came up with for TMY using Diafine.

With empirical film speed testing in bright sunshine here, I got a speed of around 250, the same speed I get with other developers like Pyrocat HDC (normal and divided), D-23 (normal and divided) and D-76.

You might find the rest of that thread interesting, for the excellent comments and advice given by other members.

I don't understand why the manufacturer claims such an increase in film speed. Perhaps their criteria are geared to small-format shooters and photo-journalistic requirements.

I'm not an expert, but it seems that one of the core value propositions of divided developers is not how they boost shadow values, but rather how they compress high values. They allow us to over-expose, not under-expose.

Many of these issues have already been discussed and illustrated at great length - in the context of Divided Pyrocat - in several earlier threads, like this thread and this thread. I also refer you to Sandy King's 2008 article about divided developers in View Camera magazine, which can be downloaded by subscribers in PDF format.

So far in my testing of Diafine, I haven't found that it does anything better than Divided Pyrocat - except that Diafine can be re-used "indefinitely". Divided Pyrocat gives even finer grain and development takes place only in Solution B. I haven't made side-by-side comparisons, but my hunch is that Divided Pyrocat is even more controlling of high values than Diafine. If there were a Divided Pyrocat formula which worked indefinitely, I doubt I'd ever have gotten around to testing Diafine at all.

[David Karp]

Hi Ken,

I am coming to this late, but if you are not using a rotary device, perhaps try using a slosher. I have one that I made for up to six 4x5 negatives at at a time. Never had a problem when I was using Diafine, and none using Thornton's variant of DD-23. Using the slosher is almost like developing one sheet in a tray at a time. If I had a dedicated darkroom, it would probably be the only way I would develop film.

[Ken Lee]

Was it too dim in there to take an incident reading in the shadows?

I returned to the scene and took shadow measurements with my (supposedly more modest) incident meter, a little Sekonic L-208 I carry as as my "backup" meter. It's lower limit is EV 3 (compared to the Pentax at EV 1), but because I was measuring the illumination directly (and not the reflections off the subject), there was enough light for a reading - even in the shadows - with a few EV's left over. Had the scene been several stops darker, I could have still made accurate measurements with this method. In a sense, the little Sekonic is more "sensitive" than the fancier spot meter... Oops.

As long as I double the film speed setting on the meter, the recommended exposure matches my more cumbersome spot measurements, exactly. I repeated the test on a few other similar scenes, and they all match - as you predicted

[Ken Lee]

Old Truck, 2013
Kodak 2D, 240mm Fujinon A
5x7 HP5+, Diafine

This time I just took an incident reading in what little shade was there. I checked with the spot meter, and everything was where it should be.

[russyoung]

With the caveat that it is 120 film (Acros) and not sheet, I have used Sandy's Diafine advice (from an ancient thread) with the Jobo set to slowest rotation for five or six years and have yet to see a problem with uneven development.

[Ken Lee]

Antique Binoculars, 2013
Sinar P, 210mm Macro Sironar
4x5 TMY, Diafine

Metered per Sandy's "quick" method: a single incident reading for the shadows with the "bottom of the line" Sekonic, and ISO set to double the effective film speed. A 1-minute exposure, calculation of bellows and reciprocity compensation thanks to the ExpoDev iPhone app.

Developed with the same batch of developer: still working after 1 month.

These binoculars are decorated with jet-black leather and brass. The reflections on the brass show the single light source, a window. The lighting was at the lower limit of the meter. Had I used a spot meter, I'm not sure where I would have placed anything.

[sanking]

Metered per Sandy's "quick" method: a single incident reading for the shadows with the "bottom of the line" Sekonic, and ISO set to double the effective film speed. A 1-minute exposure, calculation of bellows and reciprocity compensation thanks to the ExpoDev iPhone app.

We should mention that Sandy learned this method from Phil Davis and his BTZS system.

Sandy