Agitation

[kully]

I was reading the instructions to my Jessops dev. tank (finally, after having used it for four months) and it got me thinking I wasn't agitating properly.

The tank has a stalk thing you put in a hole in the top of the closed tank. When the stalk is turned the reels inside the tank also turn and as they're sitting on a zig-zig patterned washer they go up and down by about 1/4" (if that).

I've been turning that stalk thing for agitation, but the tank text says that stalk thing is used to get rid of bubbles on the film and that the tank should be inverted for agitation.

Anyone have any ideas? (I could just develop a roll of film, but I can't for another couple weeks).

 

[sunsworth]

I invert - constantly for the first 30 seconds and then 10 seconds every minute - 4 inversions in the 10 seconds.

I'm assuming that you have a lid for the tank, could get messy otherwise ;-)

Steve

 

[kaiyen]

Swirling is not quite as effective for disrupting flow as inversion is. If the uneven washer thing at the bottom moved the reels up and down a bit more it would probably be close, but as it is you risk getting uneven development with just swirling.

I rotate while inverting. Kinda best of both worlds, I guess.

allan

 

[dnk512]

Anyone knows how do I agitate 'without rotation nor inversion'? State so on the instructions of a film, and I am not sure what the agitation movement should be.

 

[jano]

Anyone knows how do I agitate 'without rotation nor inversion'? Show that on the instructions of a film and I am not sure what the agitation movement should be.

Sit it atop a drying machine or take it for a drive in a diesel or use some rodinal stand development 1:1000000 and wait for an earthquake 😀

 

[Ash]

Apparently, you should stick to one or the other. Inversion or swirling. Well thats what most instruction books (that the Photography teachers use) say.

If you swirl, the zig-zag is to break up the flow I think, and you're meant to tap the container against the sink or side of the surface you're using, to get rid of bubbles.

I learnt the hard way (for the first time in over a year of developing my own films on and off) not to agitate too much, or you may end up disturbing the development toooo much. so I'd avoid a very rumbly drying machine.

 

[kaiyen]

Is it possible to disturb developer flow too much? What are you seeing? Surge marks?

There is a subtle but very important difference between frequent/fast and violent agitation. You can't really agitate too much. You can agitate too violently.

allan

 

[Trius]

Sure you can agitate too much; it depends on what developer you are using and the effect you are after. Stand and semi-stand development are based on that premise.

 

[kaiyen]

Trius,
But I don't think that's what the previous poster meant by agitating too much. Somehow I don't think edge effects and/or compensation are the issue in that statement.

allan

 

[John Bragg]

Surely, one of the main advantages of reducing agitation, is the control of highlight values to produce a negative with more information. And that translates into a print with better tonal rendition with less burning in. Essentially keeping the negative within the capabilities of your chosen paper ? ............ J.B.

 

[kaiyen]

Yes, reducing agitation helps to control contrast. However, it is far better to reduce _time_ to do that than changing one's agitation methods. Agitation technique should remain consistent for all rolls unless you are going after a particular effect or result that _requires_ a change in agitation.

For instance, if I want to maximize edge effects and compensation, I would extend development time and reduce agitation. Perhaps go all the way out to semi-stand and stand development.

Other than that, though, I agitate the exact same way for all film in all developers, and control contrast by changing time.

allan