Agit-prop poster by Vladimir Mayakovsky

No, not that kind of Agit Prop; proper agitation. You know, that thing you do to make sure that your film gets developed evenly. It’s not a very glamorous subject, not nearly exciting as the miscellany of Unsharp Masking, but like anything else photographic, there’s more than one way to go about it.

Types of Agitation

• Rotation: Going in circles.
• Inversion: That’s turning it upside down.
• Lateral: Slide it side to side.
• Stand: No agitation. Just let it sit there and stew, for something like an hour.

Stand development seems to have a lot of adherents in the Rodinal crowd. It appeals to my lazy side, but not my impatient side, so I’ve never given this one much thought. It’s only practical with developers than you can dilute heavily, which is necessary because your extending development time from minutes to hours. Supposedly this results in very long tonal scales. Perhaps I’ll give this a shot when I get more patience. It’s on the schedule for after I turn forty along with large format photography and mixing my own chemicals.

Lateral agitation doesn’t seem to be very popular, but the idea here is that you slide your tank back and forth over the counter to create a wave that moves the developer around. If you ever developed prints the idea should be familiar. Unfortunately, it doesn’t seem to work very well. I always end up with streaks around the sprocket holes when I use this method. If you think about it for a minute, a wave sufficient to redistribute the developer is probably going to leaving part of the film hanging dry for a bit; that’s not a good thing. The effect would seem particularly questionable if you are using deep tanks. Not recommended, but it might have some merits it your tank is too leaky for inversion and doesn’t have a paddle for rotation. Insert here bad joke about leaky canoes and no paddles.

Inversion seems to get all the love on the forums. And it does work. Turning things upside down does have a way of mixing them up, but - there’s always a butt - you need the right kind of developing tank, namely a stainless steel one with a good lid. Although you can invert Patterson and other similar tanks with autoload reals, these tanks have a tendency to leak. Also, the funnel lid on them prevents the developer from getting back into the tank proper - and thereby onto the film - in the most expeditious manner. This is fine for long development cycles, but for times short of 8 mins, you run the risk of uneven development. If you must invert, buy the old fashioned stainless tanks with the simple rubber lids.

Rotation is my favored method. You can only rotate really effectively if your tank is equipped with a paddle, although I suppose you could do a little darkroom bowling with a stainless tank; that would give you some effective rotation. The paddle method is far less leak prone though, mostly because the tank stays upright the whole time. Of course this only works if your tank has a paddle. This is one more reason to get a Patterson tank or something similar. Fancy auto loading reels and paddle agitators are where it’s at for the modern darkroom ;-).

How Often and For How Long?

Those streaks are a sure sign of insufficient rotational agitation.

The easy answer to “how often” and “how long” is written in the instructions for the film and developer of your choice. Most Kodak films seem to suggest 5 seconds agitation for every 30 seconds. Ilford seem to favor 10 seconds every minute. Ilford film in Kodak developer? You could split the difference, but I’d go with whatever is recommend for the film if there is a conflict. I think I can see a difference in my negs between the Ilford and Kodak methods. Following Kodak’s guidelines seems to get you whiter whites, but I’m entirely sure that the laundry standard should be applied to photography.

Follow someone’s guidelines, whatever you do, at least at first. Slack off on the agitation and you will get uneven development and perhaps underdevelopment. On the other hand, super aggressive agitation will get you burned out highlights; developer gets used more quickly in the highlights, so bringing fresh developer to the highlight regions more frequently will develop the highlights proportionately more than the shadows. I think the same principle run in reverse is the idea behind stand development; low agitation allows developer to expire quickly in highlight regions but linger in the shadows, where it will continue developing. It seems like it should work, although there’s a fine line between reducing contrast and under-developing. I’ve experimented with increasing the interval between agitations when push processing, and it does seem to give you a little more density in the shadows. These are subtle effects though. Be prepared to experiment and risk a couple of uneven rolls.