Over agitating

I noticed when I developed my first sheet films today that I agitated the trays more or less continuously (not much else to in the dark).
What is the effect of over-agitation on the film and what is the "correct" agitation for tray developing?

r

Mats

Good Afternoon, Shimoda,

Increasing agitation tends to increase negative contrast. If you "more or less continuously" kept the developer moving randomly across the film, using the film manufacturer's recommended time for continuous agitation, you're probably close to proper development.

Konical

If your film was in an open tray and you were gently rocking it, I dont think it will have, much, if any effect. Check the negatives you just completed, if you think they are too contrasty, adjust next time. This is always a trial and error hobby, until you settle on a method that fits your style. Congrats on getting through your first set. I'm happy to see there is no mention of mistakes, so you must be doing it right.

Rick

The is no such thing as over agitation. There is only uneven agitation where the tank/reels, hangars or whatever are agitated in such a way as to replenish parts of the neg, but not others.

Continuous agitation will give about the same development as 115/120 % equal time with agitation and rest periods.

This has been proved many times in tests with agitate and rest compared to continuous in a Jobo processor.

You will also find agitation 1 every 15 sec is the same as continuous.

Agitating provides the film a fresh amount of developer. I don't know how fast the film layer exhausts the current amount of developer above the film. But I think at some point it doesn't matter if you shake the tray once 15 seconds, or every second. If you go into the other direction and shake once each 3 minutes you will get a change because the developer above your film layer gets exhausted (first in the highlights).

The time depends on the dilution of your developer.
Maybe someone has some technical info about the time from which it doens't matter how often you shake it?

Thank you all.
What I noticed whas that the deep shadows on the negatives were really black. More or less only filmbase left. But they were difficult shots. One was 25 seconds indoors and the other was an exposure with open shutter and flash. I must do some more experimenting with this. It is nice to be able to make a contact copy that is almost big enough in itself.

r

Mats

Clear shadows on your negative have nothing to do with too much agitation. They are signs of underexposure (or possibly too little agitation if it's causing underdevelopment, see below). Increased agitation, as mentioned above, is the same as increased development time, i.e., more development.

More development will, if anything, increase film speed and thus shadow detail, not the other way around. If your negatives are evenly developed and you are comfortable with your agitation scheme, adjust time if you need to (more for more contrast, less for less contrast). If your shadows are blank, adjust your EI accordingly (which might mean you have to decrease development a bit).

For what it's worth, however, you may be underagitating and thereby reducing both contrast and film speed. I have found tray rocking to be totally inadequate. If you develop just one sheet at a time in the tray, try lifting it out of the developer, turning it 90° and re-immersing it every 15 seconds after an initial 30 seconds of continuous agitation. Again, when you change agitation schemes, you will have to adjust development time accordingly (if you like the contrast you're getting now...).

If you want to develop more than one sheet at a time, you will have to learn to shuffle. There are lots of posts here and elsewhere about shuffling techniques (many from me), so a search or two should turn up lots of info.

Also, the biggest problem with agitating in trays is too much edge density caused by developer swirling around the edges of the negative when immersing them. Avoid pushing the negative down quickly and causing this turbulence.

Best and have fun,

Doremus Scudder
www.DoremusScudder.com

I agree that what you are describing in the shadows is under exposure. What are your hilights like?....That is what determines your development time (subject to the proviso that you developed the sheet minimally for shadow detail to come out...but I am assuming you did that).

Not to take this post on a tangent, and given the replenishment issue, does anyone know if stand development in a tray (is that an Oxymoron?) is possible/acceptable, or does it have to be in a tank (where gravity might help in replenishment)?

Rgds, Kal

The shadows are most likely underexposed. As I said they were shot without much measuring. Just a quick check with the dig Nikon.
I was amazed that a camera made sometime in the 1920:s still could produce images. Fantastic. More experimenting needed.

r

Mats

mats

how many sheets of film are you processing at once
and how are you processing them in the tray ?
there are several ways of developing sheet film in trays ..
which include shuffling, and rocking ...

i always shuffle the sheets in a tray ...
both hands in the tray, one on the side keeping the stack in line
and the other pulling the bottom sheet and flopping it on the top.
i do this from anywhere from 8.5 - 20+ minutes ...
sometimes rapid, sometimes slow and sometimes, after i go through a whole stack ( i count the sheets too )
i take a rest and walk to, squint and read how much time is left on the clock ... and then back to it ...

i usually do a few sheets first to adjust my time ... and then a whole bunch afterwards ...


have fun!
john

jnanian:

As this was my first ever tray development and I had only 2 negs, I did them one at a time.

r

Mats

Mats

There are four variables when you develop a film.

Developer, Time, Temperature, and Agitation.

It is like cooking in the sense that you use these variables to cook up something you like and in that it takes practice to cook up something you like.

If you change one of the variables and you will get a different result and can see if you like the change. If you change two variables at one go and you won't learn as much.

Check this out. (there was a url link here which no longer exists)