Working Characteristics of Calbe A49 Developer

From reading old Photonet posts and the information at the J and C website, I know

that Calbe A49 is supposedly equivalent to the prewar formulation of Agfa Atomal (or

Atomal F, according to some). However, no one seems to have commented on the

working characteristics of this developer, especially in comparison to other fine-grain

developers.

 

Does Calbe A49 have any advantages over fine-grain developers more commonly

available in the U.S.? Does the fine grain come at the expense of tonality or speed?

Any other observations based on working with the stuff? Any good reasons to give it a

try?

 

Thanks,

 

Charles Hohenstein

It's highly unlikely that a pre-war developer that is not of excess sulphite type (e.g., D-76) would offer anything of value with today's emulsions. Masny of thse developers cause severe loss of emulsuion speed.

Even though this was back in the seventies. An even though this was done with the "now" old Tri-X.

Judge for yourself--

 

http://f1.pg.photos.yahoo.com/ph/erind@sbcglobal.net/vwp?.dir=/My+Photos-experiments&.dnm=Atomal_Tri-X.jpg&.src=ph&.view=t&.hires=t

 

This was at the ASA 400- should have used 250.

Never say never till you've tried it and failed.

Atomal is supposed to be an excellent developer with good grain characteristics. I've never used it but I know a couple of photog's who did (and probably still do), a review I have from the esteemed 'darkroom' magazine (RIP) also gave much praise to this developer in the 80's. Also, and I can't remember where I got this information (so take with a grain of NaCl) but apparently, it could be a Catechol based developer, one of those pre-war developing agents, supposedly no good with any of today's emulsions. ;-)

Charles;

I've used A49 from JandC with Efke films (25 and 100). It looks a lot like D76 to me, (in other words, everything came out just like it should). I did film speed tests on the Efke 25 and 100 (I havn't used the 50) using D76 and both delivered very close to true film speed. The grain of the 25 is very small and the 100 is a little bigger, but not as big as Tri X. Although I havn't done these same tests with the A49, I have souped some Efke film in it and I can't really tell the difference between it and D76. Seems to be the same full rated speed and grain structure. I bought it when I was ordering film from JandC just to give it a try, along with some R09. I like them both.

 

Dean

Not knowing what the formulation is, it's hard to say. Many pre-war developers are unusable with today's emulsions. They cause huge speed loss or dichroic fog.

Gee Mike, I guess that means we shouldn't be using D-76 since it is a "pre-war" formula. Or Rodinal. Or Beautler's. Or Amidol. Or any Pyro formula.

My impression is that JandC is catering to a niche market, selling boutique items to folks who are interested in recreating the look of a bygone era. Assuming this is a fair reckoning then it would follow that it's reasonable to combine A49 with a suitable film from JandC or other supplier, printed on an equally suitable paper and possibly even developing the prints in a particular type of developer.

 

Heck, it might even be necessary to add a veteran camera and enlarger of that general era or type to complete the equation.

"Garry D. Lewis , oct 26, 2003; 10:03 p.m.

Gee Mike, I guess that means we shouldn't be using D-76 since it is a "pre-war" formula. Or Rodinal. Or Beautler's. Or Amidol. Or any Pyro formula."

 

 

Did you see this post:

 

Mike Scarpitti , oct 25, 2003; 11:46 p.m.

It's highly unlikely that a pre-war developer that is not of excess sulphite type (e.g., D-76) would offer anything of value with today's emulsions. Masny of thse developers cause severe loss of emulsuion speed.

 

...and of course you use DK-20 today?... amd Sease #2?

I have been using Calbe A49 in 35mm with agfa apx 400 rated at

around EI: 160. I dilute it 1:1 and process for 9 -10 minutes at 20

degrees. I find that this developer delivers finer grain than d-76

as well as nicer more delicate highlights. It uses a ppd derivative

as a secondary developing agent along with hydroquinone and

perhaps some others.

 

The ppd may help provide the finer grain and better highlights

which are quite apparent to me, at least with apx 400 and delta

400. This developer has an advantage over microdol-x and

perceptol in that the developing times are much shorter when

diluted 1:1, this is probably because of the hydroquinone, which

makes it more active than a metol only developer.

 

I recommend that anyone who likes apx-400 in 35mm or 120 try

it in this developer, It seems like a perfect match to me.

No Mike I don't use them TODAY. But I have experimented with them in the past (1974)- using Tri-X. Sease#3, Champlin 17, Amidol film developer, Windisch Pyrocatchenol, ABC Pyro, Neofin Blu and Rot, and others. All worked with that "modern" film emulsion. All were "stable" and only cost me, at the most, one f/stop of speed.

 

For those who would like to see the possible formula--

 

http://www.pofig.net/view.do?action=Details&type=chemistries&id=108

It is interesting to read the formula, I had no idea that it contained

catechol. I am also curious how the formula for atomal differs to

that of atomal-f. I believe that the "atomal" component must be

the ppd derivative as they suggest that it can be replaced with a

color developer component which are usually ppd derivatives of

some sort.

 

BTW Charles I believe that when it is used undiluted A49

reduces film speed up to a stop like microdol or perceptol. When

diluted 1:1 the speed loss is probably only about a third of a stop

or so compared to d-76.

Charles,

 

I've used A49 diluted 1:1 with Delta 400 and was pleased with the results. Diluted, there was little or no loss of film speed when developed to normal contrast. The grain size was amazingly small. I compared the grain structure of Delta 400 developed in Xtol 1:1 and Agfa APX 100 developed in Diafine with that of Delta 400 in A49. In both cases, the grain of Delta 400 in A49 was finer. Like Matthew, I liked the gradation from this developer. The Delta 400 also scanned very easily. One thing you don't get with A49 at 1:1 is a noticeable edge effect. Diluted, the developer resolves detail quite well, but the enhanced/apparent sharpness you get with developers like Rodinal, FX-39, and Diafine is missing. I wish I had taken the time to compare this developer to Microdol X or Perceptol. My gut feeling, based on the results I received from Perceptol in the past, is that A49 produces even finer grain. When this developer oxidizes, it produces a black indelible stain much like oxidized C-41 (color film) developer.

If it IS a ppd compound, then they have taken Meritol (MCM)(6 grms ppd+10 grams Pyrocatechinol) and added Hydroquinone for either added contrast and/or superadditive effect. Assuming the formula is the correct one.

I used a lot of Atomal back in the '70's-80s. I used to rate Tri-X at ASA 250 and get very fine grain, but great highlight and mid-tone seperation. It was NOT at all like D-76, nor any other pre-packaged developer around then or now.

AGFA designed Atomal to be used with faster films, say 200 ISO and above. It gives finer grain and does not blow out highlights. You don't get the compressed mid-tones which can sometimes happen when using D-76. I've got some A49 from J and C and plan to use it with Foma 200. If it's anything like the old Atomal, you're in for some really good negs. Disregard any negative comments about "pre war developers" "uncoated lenses" and the like. Newer is not necessarily better. J and C seem to be building a business model on this and deserve our support.

The formula that I have for Atomal contains hydroxyethyl-o-aminophenol (Agfa's Atomal developing agent), catechol, and hydroquinone. Curiously, the package of Calbe A49 contains a warning for hydroquinone but not catechol. Catechol is said to be more poisonous than hydroquinone and should be listed on the package. Therefore, A49 may not contain catechol. However, catechol has a pronounced phenolic odor and its presence could easily be detected once the package is opened. Hydroxyethyl-o-aminophenol is a fine grain developing agent and this developer probably produces grain finer than D-76.

a belated addition to this debate. I have recently purchased some old

5l packs of ATOMAL & REFINAL. There is no doubt that ATOMAL is not faux D76; it delivers beautifully modulated negs with no mid tone compression. Not unlike dilute PERCEPTOL but without speed loss. This is some developer. But does anyone know the characteristics of REFINAL, which, like ATOMAL, will soon be out of production?