Archived posting to the Leica Users Group, 1999/09/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> Showing my ignorance.... > > what is the process for "split D-76"? Or "split developers"? > > Hmmmmmm (the only stupid question being the one you wanted to ask and > didn't....!) > > Bob Keene Split Developers ================ Wow, man, this it technical stuff and gets confusing real quickly, but stick with the program, cause it's one of the great hidden joys of b&w photography, especially the kind of stuff people do with their Leicas. I was introduced to it by Boston documentarian Roswell Angier (anyone here know him?) when I lived in his attic for six months. Essentially it allows you to expose a roll under vastly different lighting conditions, even at different speeds, but so long as you have looked after the shadow exposure, you should end up with not just printable, but beautiful negatives, with long tonal scale, fine grain, and no blocked highlights. I will outline the process here, but there are better references in THE FOCAL ENCYCLOPAEDIA OF PHOTOGRAPHY, THE DARKROOM COOKBOOK, THE PRACTICAL ZONE SYSTEM, BEYOND THE ZONE SYSTEM and ANSEL ADAMS: THE NEGATIVE. There are also some resources on the web at www.heylloyd.com. Finally, it is a continual source of discussion on rec.photo.darkroom, and a search for 'split d-76' or 'divided d-76' or 'divided d-23' etc should turn up articles by me and others discussing the process. Skip down to the bottom of this post for details of chemicals, times, films etc. The basic premise is: the film goes through two development baths. The first contains either (1) regular developer (D-23 and D-76 are faves) or (2) a modified developer (such as D-76D) which has no alkali (accelerator) in the solution. In any case, time in the first bath is restricted to (usually) 2-4 minutes. Whatever development DOES take place in this bath is restricted so that highlights develop to just about where you want them. Now the clever bit. The film is transferred, without washing, to a bath of alkali such as sodium carbonate, kodalk (sodium metaborate) or borax, and left there without agitation for 3-5 minutes. What happens in this bath is a function of the developer which has adsorbed into the film emulsion and which is activated by the alkali. In highlight areas, the developer quickly exhausts, and development essentially stops. In shadow areas, however, the developer exhausts much more slowly and development continues, increasing the density of shadow detail while not blocking up the highlights. The film is then stopped, fixed and washed as normal. Ansel Adams claims that with D-23 this results in the equivalent of an N-2 contraction. If this were all that happened, it would not be interesting, but - especially with a developer like D-76 - the actual effect is a more interesting. You essentially (ideally) end up with a negative which has very good LOCAL contrast - ie within particular areas of tonality - but a compressed tonal scale overall, which one hopes is matched more closely to your paper du choix. The upshot is they are easy to print, and have beautiful greys, and retain detail in highlights that would burn out in another developer. If your idea of a nice print is that HCB Zone 5 look, this is a process you should try. Prints from these negs have a very particular, mellifluous, look which you can spot a mile off once you've seen it once. The big difference from standard N-1 or N-2 contractions is precisely in the shadow values, which have greater density and tonality. It is almost as if you give the highlights an N-2 development and the shadows an N development. Overall highlight density can be controlled by the time in the first bath and the choice of developer. Overall contrast can be most easily controlled by choice of developer. Shadow support is a function of time in the second bath, but improvements after 3 minutes are marginal (you can leave it in as long as you like). There are pros and cons to this process. Pros ==== 1) Very simple and quick 2) Not heavily time or temperature dependent 3) Does not generally require a big reduction in film speed. Some people claim a gain in film speed of up to a stop. I lose half a stop, personally. 4) Fine grain 5) Cheap 6) Very printable negatives with fine tonal gradations 7) No blocked highlights 8) You can develop different films in the same batch Cons ==== 1) You need to run some tests to get the best out of it 2) You may (or may not) need to mix your own chemicals (but it's bloody easy) 3) Done badly, you may end up with horribly flat negs 4) Pretty unforgiving of underexposure 5) Doesn't work well with thin-emulsion films such as Delta or T-max. Basically, it's Tri-X, chaps -- but the results can be amazing. 6) If you agitate too enthusiastically in the first bath you end up with horrid drag marks around the perforations. Gently does it! 7) Fog levels may be high (though I have not found this). However, Ansel says you can simply 'print through' this. To me the pros far outweigh the cons, but you really have to suck it and see. It's worth sticking with it for a few rolls, because you need to get a feel for the way the various parameters interact, which is NOT necessarily the way ordinary developers work. The key, for me, is finding your Zone III shadows and exposing for them without cheating. Sometimes this means shooting 1/125 at f8 in blazing sunshine. You just have to grit your teeth and trust your meter! The highlights genuinely do take care of themselves. The single greatest plus is getting a whole roll from a manual camera in changing light when you couldn't keep pulling out the Sekonic - and they are all printable (and readable from the contact sheet). To me the 'look' resembles XP-1, with somewhat crisper grain. My times/temps/speeds are the following (all with Tri-X rated 320, all @ 68F) SPLIT D-76 ========== Stock D-76 3 mins* 5s/30s gentle agitation 1.5% Kodalk 3 mins No agitation *increased to 4 mins if whole roll shot on a dull day, maybe pulled back to 21/2 or even 2 if the light was blazing. SPLIT D-23 ========== Stock D-23 4 mins 5s/30s gentle agitation 1.5% Kodalk 3 mins No agitation Of these two processes, I prefer the first, which gives negs with more 'snap'. However, if you are shooting flash at night or in Californian sunshine, the second may be a help. D-23 is not commercially available - you have to make it up yourself - but frankly it's no harder than mixing D-76 from the tin. It only has two components - Metol and Sulfite - both of which are cheap and widely available. D-23 is a fine developer in its own right, and worth playing with. In particular, D-23 can be stunning with TMAX -- no more blocked highlights! As for 'true' split D-76 (D-76D, which you also have to mix yourself), I have no experience with it, but others claim very good results, something like a combination of the above two processes. I have probably made some crass errors in the above, but it reflects my own experience. Your mileage may vary. - -- Johnny Deadman "There is no need for the writer to eat a whole sheep to be able to tell you what mutton tastes like. It is enough if he eats a cutlet. But he should do that" - Somerset Maugham