AN-15 Developer, any experience-results-comparisons ?
In the often quoted Altman and Henn paper, Photo Sci Eng: 5 129, 1961, they looked at variants on the D23 formula the highest acutance was with AH15.
Metol 0.25 g
Sodium sulfite 10 g
Sodium metaborate 20 g
Water to make 1 litre.
Obviously not a tricky make but Google doesn't throw up anything much before I have a play has anyone been there, done that?
I don't have easy access to a densitometer so my results are going to be empirical and it would be of interest if results are out there.
Just noticed stick fingers made it into AN in the title, Mod to change, not editable for me, apologies? C
Very interesting formula! Just 10g of sulphite and 20g of Kodalk?? It must have very short life after mixing?? Any results to share yet?
This developer is starved for developing agent. It is not uncommon for these to give good sharpness and fine grain, but something has to give in this.
I think that the curve may bow over in the higher densities.
This developer was tested with older K-grain emulsions. IDK how it would work with modern blends or T-grains.
Joe and Dick did that work just before I got to EK.
I was certainly aiming to treat it as a "one shot". Is this strength of components, going to produce increased adjacency effects?
Originally Posted by Photo Engineer
Isn't it the case that where you are relying on a carry over in the emulsion with two bath that "modern" films will not work "well" ? (lots of inverted commas as I am aware these are relative and uncertain quantities)
I started this by reading up on two bath D23 but there I am told development is present in the first bath so somewhat different from most two bath developers ?
I am awaiting the paper from the library but i assume as PE has not corrected it, the formula is correct?
I am aware this is a one bath formula BTW just that I came across it looking at split D23.
The formulae and acutance with AH-15,16,17,18 are given at the end here by Gudzinowicz:
They were OK with Panatomic X, not with Tri-X.
I tried AH-18 about 5 years ago.It's like FX-1 or Beutler with lower pH and longer time.I think your formula is AH-18.
I did not try the AH-15 version.
Years ago they used to develop films in acutance developer to make the prints look sharper.
Crawley called this "The acutance era".
This type of film that gave strong acutance effect is not made anymore,eg, Panatomic-X, Plus-X,Adox CHS-25,50,100.
Modern films with tabular grain show much less response to acutance developer,but have finer grain.
Last edited by Alan Johnson; 11-03-2012 at 05:20 PM. Click to view previous post history.
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
Alan, appreciated. I had missed that link. It does look like AH-18 not 15 and of course Crawley's FX-1 was the same era. The Stoeckler and Thornton Two Bath are all in the same family, I just wondered how 18 went taking that principle mixture to the extreme.
In the extreme, with these old films,more dilution and stand development,dark objects on the print have white lines round them.I obtained this result with Plus-X in FX-1.If you can lay hands on some of the recently discontinued Adox CHS 25 or 50, perhaps AH-18 would be even more so.
For practical purposes Crawley recommended FX-2 with reduced agitation, the Glycin minimises streaks.This works with APX 100 as well.
I don't have the formula for any of those and on my screen the formulas at the referenced site are too garbled for me to read. I can comment from theory that development starvation decreases development in higher density regions and changes the image structure. Generally, the inhibiting effect of released bromide will kick in, but then as development slows down other things begin to take place, but yes, adjacency effects would be expected here.
Two bath developers are problematic. They can work with modern films, but the problem is this. Old, thicker films absorbed more of the first part and carried it over to the second part. Today, films are thinner and harder. They carry over less of the first part. In fact, 2 part developers are very hard to control from film to film due to thickness and hardness variations. For this reason a 2 part developer must be adjusted for every film.
I would suspect that a 2 part developer could be devised for a modern film simply by increasing the concentration of the first part by 2x or 3x.
Kodak Research in the UK did much more work on Acutance developers and Kodak Ltd release HDD, they also made a Rodinal type developer Kodinol, neither were available in the US.
It's often forgotten that Kodak's Research facilities in Rochester and Harrow were both set up by Mees after Kodak bought Wratten & Wainwright, and many of the senior staff in both the US &UK had worked together at Wratten & Wainwright. (Up until the1950's).
In practice mainy of these older acutance developers work better with modern T-grain & similar films than they did with films from the late 60's and 70's. So Rodinal gives excellent fine grain with films like APX 100 and Tmax 100 which is why it staged a big revival of usage.
One has to be careful with edge effects as when overdone they lead to very strange looking prints.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.
~Antoine de Saint-Exupery