Dear all,

I bought a Philips development tank for roll film recently.

It came with a little stick. It is to spin the film holder in the tank.

My question is, do I have spin the film holder the entire development time? Or do I have spin it when I would normally shake the tank top agitate it?

Pelle

Kodak used to provide (probably still do?) very specific instructions about film agitation during development. Usually, IIRC, agitation was not continuous but was on the order of, say, 5 seconds out of every 30 seconds until the recommended time of development had been reached. Over-agitation tends to cause streaking on the film, especially with 35mm stock because of turbulence around the sprocket holes. Of course, that particular problem doesn't exist with 120 or sheet film. But there might be a problem with image density even so.

As the other Henry says usually the agitation is not continuous.
To give a specific answer, read the fine print of the data sheets for the film and chemistry that you are using. I know that is a PITA but that is also the best way to get the required info!
There isn't much difference between twirling the spool with a rod, inverting the tank or shaking it without inversion. Use whichever is most comfortable for you with your particular tank.

C. Henry

hey Kodak has continuous agitation data its mostly for autoprosser like JOBO
less time need with continuous agitation

banjo

Though it's not that brand, I have a similar tank. I don't really like tanks that only have the twirly stick. They can be prone to giving uneven development. I keep the thing because it handles film sizes from 127 to 116/616. When twirling the stick, it's a good idea to spin it both directions. Continuous agitation requires roughly 20% less time. It builds density (contrast) faster. As with any method, the data sheet times are only starting points. Variables in shutter speeds, filter factors vs film sensitivity, the developer in use and it's dilution and age, the water, etc can all change the time. Good luck in your endeavors.

Dear all,

Thanks for your comments.

Pelle