I'm just curious. When I first got into developing, I encountered 2 types of agitation at once; the typical techniques (which of course vary a little according to manufacturer, etc.), and, since I shot a lot of Technical Pan in Technidol, I also encountered the 'up and down', non-inversion technique reccommended by Kodak for this combination. That is the only time I've run across this (the 'up and down' technique), but I have had far greater results with it for e very combination I've used (old emulsion, new, old developer, new, pyro, Technical Pan and on and on), than the inversion technique.

I've avoided teaching seminars on Basic Black and White Processing because of this, since in my experience I am the only person who uses this agitation technique--and I am uncomfortable teaching students something I myself have little faith in, i.e., the inversion technique.

I have never had uneven development with it; whereas I have with the tried-and-true "normal" way.

I have never encountered overall density errors with a known combination; whereas with the "Normal" technique, again, I have.

This isn't a question of "if it works for you, use it", but rather I'm curious why so many people look at me sideways when I tell them how I agitate, when everything points to the conclusion that "my" technique is so...predictable.

I can't imagine that, if someone else were to use it, their results would differ much (I am far from methodical about it...); nor can I imagine I am doing the regular, inversion technique so differently than others (actually, I learned that in a class, and everyone did it essentially the same way...).

Just looking for feedback (& maybe some assurance that we all live on the same planet...?)? Or maybe I need a life...:-(

-- shawn (shawngibson_prophoto@yahoo.com), August 23, 2000

Answers

The advice I've always heard is find something that works for you and stick with it unvaryingly. I have always used the "torus" method described by Adams in his book THE NEGATIVE, and it works for me so I haven't changed it for 15 years.

-- Ed Buffaloe (edbuffaloe@unblinkingeye.com), August 23, 2000.

I agree, Ed. But I don't understand why the 'up and down' method is so...unknown. Maybe it is a matter of something simply being so predominant...for no apparent or necessarily negative reason...that there has never been a need for any other method to become popular. Who knows?

Maybe this is a philosophical approach to something which really doesn't need to be philosophised over, unlike the perspective of bats and the existence of perfect islands...

-- shawn (shawngibson_prophoto@yahoo.com), August 23, 2000.

I agitate aggresively too Shawn(martini martini martini then twisting twisting twisting)... don't fret.. YOU ARE NOT ALONE, I use plastic tanks and reels so it ends up the same as gentler agits with SS I'd imagine. My tray processing techniques are all over the map... in technidol I grab alternating corners and flail on that sucker 5 every 30 and rock roughly throughout... with trix in nearly all my devs(RS,Perceptol, DD76) I rock as gently as a baby for 5 every 30. I've deluded myself into all kinds of stoopid rationalizations about my weird and varied lightsource(s), devs and so on but it's really just superstition. I don't figure it matters as much as consistency. Now if i can just remember which method goes with which film in which dev for what source? Oh geez...

I worked in a lab too so I've seen bad methods (GEOFF PEVETO)... that's the one where you put the tanknreels on top of a wobbling and ancient model 3 wing lynch while it's torturing client's e6 and forget about it for 30 minutes or so. Or you could plop it atop a silver recovery unit that's about to explode due to a few thousand missed deplatings... they wobble pretty good (throw off some pretty fireworks in the end too!).

-- Trib (linhof6@hotmail.com), August 23, 2000.

I agitate to the tempo of Bach's Brandenburg Concertos (I especially prefer #3).30 seconds continuous then 5 seconds at 30 second intervals thereafter with a sharp rap on the counter every minute.I'm using stainless steel reels and tank. I'm using the inversion with a twist method ala Adams.It works for me...what can I say.

-- Robert Orofino (rorofino@iopener.net), August 23, 2000.

You are not alone...you are not alone...you are not alone..

I too use an abnormal agitation technique...the half-full tank method...and it works great but every time I recommend it to anyone there's a half-dozen messages posted saying why it's bad and won't work. Of course none of those posters have ever _tried_ it....

I've never heard of anyone using the cocktail-shaker method for anything other than Technidol, but otoh since the idea of agitation is to move fresh developer to all of the emulsion surface as quickly as possible upon initiating an agitation cycle, I can't think of any reason to not do it that way other than slinging developer everywhere from a leaky tank.

So look at it this way; it works for you and if you can teach it to others so they can make it work, why not? The only thing that counts is what works.

-- John Hicks (jbh@magicnet.net), August 24, 2000.

When teaching, my approach is, 'here is how I do it, and it works for me. Now let me tell you about some other ways of doing this.'

I also emphasize that for every topic we cover in a basic course in an hour or so, we could probably develop a one or two semester course. That is, there is SO much to photography, and there are so many different ways of doing everything that it impossible to go into all the variations, and, ifs or buts, in a basic b&w course.

chris

-- Christian Harkness (chris.harkness@eudoramail.com), August 24, 2000.

Hi Shawn, Back in my roll-film back days I shot lots of 120 film and developed it in Nikkor steel tanks using the "famous" torus method. This gave me uneven development occaisionally (higher-density stripes along the long edges of the film), so I dedicated a day to experimenting with agitation techniques. I exposed roll after roll of film under the enlarger, loaded them on reels, developed them using different types of agitation, inspected them after a minute in the fix, and threw them away. In the end I determined that my problem was from a combination of filling the tank too full and under-agitation, but I also found that a lot of different agitation techniques work just fine. I now (for the rare occasions when I develop roll film) use the "martini shaker" technique, shaking and turning the tank really vigorously 5 seconds every half-minute after a 30 second intial agitation, but I've used the up-and-down only method and the rotary twisting method successfully as well (I had one tank with a leaky lid which I never inverted). The main thing is to do the same thing consistently so your results don't vary. Agitation technique can have an effect on development time (more vigorous agitation shortens the time and vice-versa). Long development times with dilute developer and only occasional agitation (once every few minutes) can be used for a compensating effect for N- negs since the developer becomes exhausted in the high-density areas but continues working in the low- density areas for some time. Again, consistency is important. As far as teaching goes, what's stopping you? Just show the students what you do, tell them what others do and let them find their own personal "style". The main thing is to make them aware of the defects possible from inadequate agitation and to be able to help them when they have problems. Regards, ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), August 24, 2000.

I've been using the reel "twirler" that comes with plastic tanks/reels for about 25 years with no problem. Four gentle back-and- fourth twists that alst 5 sec. every 30 sec. I've used stainless reels in the past. I liked the reels but hated having to lift the tanks out of my water bath to invert. So messy!

-- tim brown (brownt@flash.net), August 24, 2000.

I recently replaced my 25 year old tank (which had no "twirler") with a nice new tank with a "Twirler" that not only rotates the reel but bounces it up and down a little. Very convenient. Negatives looked great until I developed a set of uniform gray card images (for zone calibration). They show decreased density in the center of the strip. I'm guessing this is due to the "twirl and bounce" agitation. Looks like I should go back to the old inversion technique. If I hadn't done the uniform exposure tests I probably wouldn't have noticed the effect for quite a long time - in fact I still can't really see it on "normal" negatives.

-- Bob Atkins (bobatkins@hotmail.com), August 24, 2000.

I have decided there is no way to over do agitation during the few seconds it takes place. I not only invert the tank, but shake it up and down too. I found the swirling motion too gentle, hence the good shake came into play as well. Sheet film is the same idea, you can't get too much movement in five seconds, so go for it. One does need to move sheet film sideways too to avoid stagnant edges.

-- E.L. (elperdido65@hotmail.com), August 24, 2000.

FWIW, for the last couple years I've been using gentler and gentler agitation (except for the first 30-45 seconds). Also, more and more dilute developers. Quality is still going up- maybe I'll end up developing in water with no agitation at all! Seriously, if it works on normal negs and shows no abnormality with even tones, use it, teach it, and enjoy it.

-- Conrad Hoffman (choffman@rpa.net), August 24, 2000.

Conrad, I always tell my students, 'if you develop your film by holding it in a toilet bowl and flushing, and it works for you - do it.'

So, maybe I need to investigate that method a bit further!

Cheers! - chris

-- Christian Harkness (chris.harkness@eudoramail.com), August 25, 2000.

When inversion tanks first came up, I read in a book that this would probably just be some kind of short-lived fashion which would soon be overcome again by the tanks where you rotate the reels at intervals. Well, the fact is, inversion came to stay. Personally, I can understand why one would prefer inversion to rotation. This (and a couple of the posts above) shows that this is probably as much an issue of belief as of physics and chemistry. I have been using "normal" inversion for all my darkroom life, and I will surely stick with it, BECAUSE IT WORKS FINE - FOR ME. Shawn wrote that this is not the kind of answer he needs, and being a physicist myself, I' curious, too. So let's look at it from the scientific perspective:

You can develop w/o agitation. The developer is then depleted near the film, and especially at places where a lot of density builds up. There is plenty of developer in the rest of the solution, so following nature's desire to keep everything in equilibrium, the unused developing agent will diffuse to the emulsion, the oxidised stuff will diffuse away, but VERY SLOWLY. That's why stand development tends to compensate contrast (see also below). If development were taken to complete equililbrium and there were enough developing agent, i.e. if we let the film simmer in the soup until it does not react any more, but the reaction does not stop because there is no developing agent any more, agitation would probably have no significant effect.

However, development is a process far from equilibrium. We won't leave the film in the soup forver, because even unexposed silver would then react increasing (at the very least) the base fog. Also, we cannot usually just wait until diffusion (a notoriously slow process) brings enough developing agent to the emulsion. So we have to help diffusion by agitating. This is supposed to reduce the concentration gradient created by the reaction, thus bringing the solution (not the development as such) to equilibrium. However, we don't want full equilibrium, as some of the effects of concentration gradients are desired (acutance-enhancing edge effect, a slight compensating effect, to name just two).

That said, what is the best method of agitation? We want the solution to be properly mixed, but there must not be any "ordered" flow patterns. Where these occur, they give rise to streaks and non-uniform development. The answer to this is turbulence. It mixes, but there is no ordered flow pattern. So why not just agitate as chaotically as possible? Because we have a third requirement, namely that we want repeatability.

I essence, that's why we have to use some kind of standardized agitation method. (It does not mean that we all have to use the same standard, but that each of us should develop his standard method, and stick with it unless there is a serious reason to change it.)

After this lengthy discussion (which mainly served to bring order to my thoughts) back to the original question: I think there is evidence that one can find a lot of different agitation methods that work. If you have shown that yours works with your equipment, there is reason to believe it does, provided that someone uses equivalent equipment. Most of today's tanks are built with inversion in mind, so inversion will work with them. I wouldn't want to guarantee that a non-standard agitation method will instantly work with a different tank system, too. It might be that the innards of your tank work fine with a specific exotic method, but that another tank system works better with inversion (or yet another method).

Sorry I wound up so long.

-- Thomas Wollstein (thomas_wollstein@web.de), August 25, 2000.

agitation

Shawn, Many years ago, in Popular Photography, a lady wrote a column , (sorry but can't remember her name), and in one series she spoke of agitation. I was having a problem with dark streaks coming from the sprocket holes into the film and her answer solved this for me. She said to turn the tank over, back and forth, for the first 15 seconds and, then, two flops every 30 seconds. (Seems too much agitation would bring out the streaks.) I've used this technique ever since. However: I DO NOT argue with your method. Whatever works for you, or others, is fine. Hope this helps. Dave Huffman

-- H. David Huffman (craptalk@lvcm.com), September 20, 2000.