Paterson Aculux 2 - I'm a fan now!
I posted while ago asking if anyone knew what this dev is similar to in chemical make up. I post again as I have dev'd 2 more 120 films in it (TMAX100 the 1st time-which I thought was a fluke), delta 100 and Pan F - Great results. Light was contrasty, so I used half box speed and used patersons times minus 15% as first guesstimate (printed on colour head), in paterson tanks with gentle agitation every 30 seconds. Printed beautifully between Grades 2-3.5 depending upon lighting of individual frames. Best tonality I have seen, great shadow detail and wonderfully held highlights! Every now and again you see something that knoks your socks off. This is it. I printed on Forte PWT. Perhaps this dev and the other materials just meshed?
I asked about similar devs as paterson has already been in receivership once and if I find out what the stuff is similar to, it gives options if they go under, something we are all becoming aware of.
As an aside, the Pyrocat HD I made is every bit as good as Barry Thorntons Exactol Lux and Dixactol (but slightly slower speed and between the two 'xactols for grain), perhaps better in that highlight compression seems less. Still early days tho. Thanks Sandy!!!
Last edited by Tom Stanworth; 12-20-2004 at 07:17 PM. Click to view previous post history.
Patersons' developers are all formulated by Geoffrey Crawley who is very well known in photographic circles in the UK and he continues to contribute regularly to Amateur Photographer magazine. These developers' formulas are proprietory so it is unlikely that there will be anything quite similar. Patersons have been around for decades and although ownership has changed over the years they seem quite secure. They don't just do chemicals but distribute a number of lines incuding professional lighting units.
As far as Aculux 2 is concerned, it & its predecessor Aculux, have also been on the market for at least 20 or more years. It is Paterson's general purpose developer and
is generally regarded as a very reliable developer which can deal with almost any film thrown in it.
Thank you, Tom. I am glad that Pyrocat-HD has proven useful to your work.
Originally Posted by Tom Stanworth
Just a comment, though I don't want to hijack your thread on Aculux. In developing the Pyrocat-HD formulas I optimized it for very low B+S since this characteristic is very important to me as an alternative printer using sheet film. High B+F values cause dramatic increases in printing times, especially when developing for the very high CIs needed for alternative processes. If you test the B+F from Pyrocat-HD you will find that it is as about as low as it can get, say on the order of 0.05 - 0.06 with fresh FP4+ film, comparable to values we see with D76 and Xtol.
Based on comments made by Barry Thornton, and because he used primarily small and medium format cameras, I am fairly certain that he would have tried to optimize his developers for minimum grain, which would also have favored increased effective film speed.
If you are mixing your own Pyrocat-HD let me suggest this. Decrease the amount of potassium bromide in the stock solution by 50-100% and you should get a significant increase in EFS. Potassium bromide is the restrainer in the formula and its primary function is to to reduce B+F to acceptable levels. However, one of the side effects of reducing B+F with bromide is a reduction in developer activity and EFS. If you use primarily 35mm and 120 film you may find the Pyrocat-HD formula better for your work if you lower the amount of bromide. This will result in a slight increase in B+F, or general stain, but it will also increase slightly EFS. Also, grain will be minimized by the increase in general stain.
Sandy, I'm a 120 film user and a bit more speed is always welcome. Would reducing the bromide have an effect on acutance, since the exhaustion of developer is involved in the edge effects? If so, I would stick with the edge effects, I think, though I'll give reduced bromide a try.
On the subject of Crawley and Paterson formulae, I'm sure I read that when one Paterson developer (Acutol S) was taken off the market, Crawley released the formula to the public as a service to those who wanted to continue using it.
Personally I have found Acculux to be a speed increasing developer. It has great tonality and good keeping abilities. The Patterson line of developers is only recently available here in the U.S. but well worth checking out . Very fair pricing too. Do not overlook Accutol for slower films i.e. ASA 100 and lower. It will produce true speed.
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This is a complicated issue so all I can offer is an opinion, and the opinion is that with Pyrocat_HD developer edge effects result more from local exhaustion around the highlights and the production of bromide at the border between shadows and highlights than from the overall amount of bromide in the solution. Consequently the type of agitation used is more important than the bromide in the formula. What I recommend as a balance between maximum production of edge effects and even development is minimal agitation with fairly dilute solutions, and increased time of development. For example, assume that your normal development time with a 1:1:100 dilution of Pyrocat-HD is 10 minutes with agitation every minute. For more edge effects increase time of development to 13-15 minutes but reduce agitation to once every two or three minutes. Alternatively, for even more edge effects dilute 1:1:150 and develop for 20 minutes with agitation once every four or five minutes.
Originally Posted by john_s