acutance developer lineup

There are a lot of choices when it comes to acutance developers, and a lot written about them, but would someone be able to make a sort of ranked list according to their edge effect strength? FX1, FX2, Tetenal Neofin Blue, Rodinal (various versions of it), Pyrocat HD etc. I'm not asking for any scientific data (although that would be great), just your personal opinion. What are the top 10 in terms of acutance?

Thanks

Yea I know. I mean providing the same film (some that reacts roughly equally to a wide variety of developers in terms of edge effects), same agitation, same dilution etc.

I've been playing around with FP4+ recently, seeing how different developers and other things affect grain, sharpness and resolution.

In regards to FP4+, so far I know that 1+100 stand developing has significantly less resolution than Xtol replenished. At least with FP4+ the so called edge effects do the opposite of what is claimed and lose detail. Though I have yet to compare it to 1+50, and 1+25 normal developing.

Adding a solvent to it along with potassium iodide improves all 3 of those criteria, need to play with it more though.

Have you tried OBSIDIAN AQUA? Fine grain AND sharpness! It consists of two stock solutions, A and B. A is the reducing agent, B is the alkali. The dilution as standard is 1ml of A plus 12.5ml of B made up to 500ml with tap water. It and FP4 Plus makes a pretty good partnership...



RR

On apug, I think there are very few post/users, who use high acutance developers. I see many discussions for fine grain dev., that right now seems in vogue. I do not agree with it, but. . . . .

Well I'm just starting to experiment with them. I ordered some Neofin Blue. As far as I have been able to read, it's one of the stronger ones in terms of edge effects

What about Formulary's FA-1027?

The "Acutance era" as Crawley called it started with the introduction of Adox thin emulsion films in the 1950s.The perceived sharpness of prints could be increased with edge effects (Mackie lines) formed by development in acutance developers.Some time ago I did some tests involving photographing wide line targets and making 10x enlargements of the edge.
In the first set various films were stand developed in half strength FX-1 and prints examined for edge effect.Now discontinued films Adox CHS 25,50 &100 and Plus-X gave the greatest effect.Intermediate were Agfaphoto APX100 , FP-4 and Pan-F+.The least edge effect was with the tabular grain films Acros,Delta 100 and T-Max 100.Tabular grain films are inherently sharper and benefit little from the acutance boost,they appear to have heralded the decline of the acutance technique,there are not as many posts about it these days as there used to be.(Scanning may have something to do with this as well.)

I also tested 4 acutance developers stand developing using the same film for each,Plus-X IIRC. Stand developing just magnifies the effect so it was easier to see on the prints.The greatest edge effect was obtained with FX-1 followed by FX-2 then Pyrocat HD then Rodinal.This is the same order as given in the tables in The Film Developing Cookbook in the chapter on non-solvent developers so it seems to me those tables are likely a good guide.IDK the original source of the tables in FDC.
Recently Adox introduced new films I have not tested.

The vast majority of acutance developers, and there are dozens, work on the same principle. That being a very dilute developer which results in localized exhaustion in areas of greater exposure. The only exception I know of is Kodak's High Definition Developer (HDD). This developer were never marketed in the US but had a following in Europe particularly the UK. It's action was based on a different principle from other acutance developers. The formula was never released but Geoffrey Crawley made a guess as to its composition in the BJ. For those that are curious the formula should be in the APUG archives.

When they are used properly these developers may produce a slight difference in the negatives but the differences are usually only noticeable using a microscope. With prints the differences are even less noticeable. The effective use of these developers requires attention to detail from exposure, development, and in printing. These developers work best in combination with good quality camera and enlarger lenses. Camera shake also negates their effectiveness. These details are more important than the actual choice of developer.

speaking of acutance developers -- why is it that, in the eyes of some people, enhanced acutance requires a certain sacrifce in terms of tonality? Barry Thornton, for example, considers Beutler's tonality »a little flat because of its compensating effect« and points out FX1's »tonal limitations«;
Otto Beyer warns against acutance developers altogether: »FX39, HRX, TFX2 etc., they all have poor gradation«.

Assuming that gradation is a problem with developers optimized for acutance, I wonder why that is. Is it because acutance requires reduced chemical action, and reduced chemical action results in a compensating effect with progressively flatter highlights, which is, in turn, synonymous with poor gradation (to these people)? Or does the perceived poor tonality have to do with the emphasized grain that acutance developers tend to produce?

TD-121.

Nope. By far it would be Billy Thornton's stand developed. The TD formula gives higher grain with little to no benefit. At best it would be second with thicker emulsions.

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I really like pyro-cat HD. no sulfite, stained, so highlught grain is masked. I like it with regular golf ball grain films. not tabular grain. I think it works well with foma. It did work real well with the old adox films. even with rollie retro 80's the edge effect is quite pronounced in stand development.

Regular Rod said:

Have you tried OBSIDIAN AQUA? Fine grain AND sharpness! It consists of two stock solutions, A and B. A is the reducing agent, B is the alkali. The dilution as standard is 1ml of A plus 12.5ml of B made up to 500ml with tap water. It and FP4 Plus makes a pretty good partnership...

RR

Click to expand...

Never heard of it before tbh. I'll post some samples when I get the chance.

Athiril said:

Never heard of it before tbh. I'll post some samples when I get the chance.

Click to expand...

http://freepdfhosting.com/aa330a94ce.pdf

RR

AntiLynd said:

speaking of acutance developers -- why is it that, in the eyes of some people, enhanced acutance requires a certain sacrifce in terms of tonality? Barry Thornton, for example, considers Beutler's tonality »a little flat because of its compensating effect« and points out FX1's »tonal limitations«;
Otto Beyer warns against acutance developers altogether: »FX39, HRX, TFX2 etc., they all have poor gradation«.

Assuming that gradation is a problem with developers optimized for acutance, I wonder why that is. Is it because acutance requires reduced chemical action, and reduced chemical action results in a compensating effect with progressively flatter highlights, which is, in turn, synonymous with poor gradation (to these people)? Or does the perceived poor tonality have to do with the emphasized grain that acutance developers tend to produce?

Click to expand...

I've wondered about this too, but more specifically what they mean by "poor gradation". If it is about gradation it seems like it should show up with a curve of the film response, but I've never seen this accompanying those comments. Has anybody generated curves for one of these. To be clear, I'm not really including Rodinal, which might have pretty good acutance, but was more of a standard developer (albeit a grainy one).

A very nice explanation, and some interesting ideas. Thank you.

Regular Rod said:

http://freepdfhosting.com/aa330a94ce.pdf

RR

Click to expand...

Regular Rod has more experience with Obsidan Aqua than I, but I find that I cannot get box speed on film with OA -- but all that means is that I have to continue the process of dialing it in.

I also like 510-Pyro, but again, I don't get box speed.

I just processed a test strip of FP4+ with Obsidian Aqua for 9 minutes, even the overexposed shots (by a few stops) are too thin. Obviously either it is too dilute and/or time is too short. On the upside, what I did notice is that there is a relief on the emulsion side, like you get with E-6 film.

Rodinal 1+100 stand, gave 38 lp/mm
Xtol Replenished gave 55 lp/mm
Rodinal 1+25, 9m gave 55 lp/mm

OA at 9m in regards to the PDF link gave 80-85 lp/mm by the looks, with fine grain that is very smooth, however, it's at several stops of speed loss, which of course I can do with other developers, modified Rodinal 1+100 stand (extra ingredients) for speed loss, about the same speed gave 80 lp/mm. The edges seem softer in OA, but its just edge contrast I think.

I'm sure this figure would drop back down if I got it to box speed or close by, even a stop under.

Though it looks like it has good potential. I'd like to see if I can exploit this relief effect more as well.


OA is the less grainy of the two samples, these are extreme crops, the grain is already very fine in both examples. The height of the top 2 chart sections represents about 1.29mm on the neg.

Athiril said:

I just processed a test strip of FP4+ with Obsidian Aqua for 9 minutes, even the overexposed shots (by a few stops) are too thin. Obviously either it is too dilute and/or time is too short. On the upside, what I did notice is that there is a relief on the emulsion side, like you get with E-6 film.

Rodinal 1+100 stand, gave 38 lp/mm
Xtol Replenished gave 55 lp/mm
Rodinal 1+25, 9m gave 55 lp/mm

OA at 9m in regards to the PDF link gave 80-85 lp/mm by the looks, with fine grain that is very smooth, however, it's at several stops of speed loss, which of course I can do with other developers, modified Rodinal 1+100 stand (extra ingredients) for speed loss, about the same speed gave 80 lp/mm. The edges seem softer in OA, but its just edge contrast I think.

I'm sure this figure would drop back down if I got it to box speed or close by, even a stop under.

Though it looks like it has good potential. I'd like to see if I can exploit this relief effect more as well.


OA is the less grainy of the two samples, these are extreme crops, the grain is already very fine in both examples. The height of the top 2 chart sections represents about 1.29mm on the neg.

Click to expand...

9 minutes is too short.

I use 12 minutes with OA at dilution 1:12.5:500 for all films and all film speeds @ 20 deg. C.

RR

sodarum said:

Yea I know. I mean providing the same film (some that reacts roughly equally to a wide variety of developers in terms of edge effects), same agitation, same dilution etc.

Click to expand...

Do you print optically or at least contact print in DR?

Dan, it sounds like you underdeveloped your OA test clip, which would also explain the finer grain you observed. The biggest advantage of OA is that with the mixing instructions given you get enough concentrate to fill a whole bath tub with this developer (at working solution strength), which means you really know it well by the time you are done with the first brew.