lighter bands at the top and bottoms of my images...it was surprising what the culprit was.

[rpavich]

Advertisement (gone after registration)

I had light bands at the top and bottom of my images and i was sure that it was a light leak from my new camera. I surfed the web and caught some discussions showing images just like mine. The suggestion by some knowledgable members of different forums (Roger Hicks being one of them) suggested that my agitation technique was to blame. I couldn't see how that could be but then found a Youtube video showing a guy who agitates much more vigorously than I'd have thought should work (not sure of his name but he's got an epic beard) and so I tried it.

 

Well...long story short, it fixed a host of little issues that I've been having; specks of chems in my negs, light bands, slightly uneven developing...etc.

 

I would have never believe that this would be narrowed down to agitation but it was.


Just thought I'd mention it for anyone who has the same issue.

[250swb]

I'm sure it would help others if you could describe the technique that was bad?

 

But usually it is twiddling the stick in a Paterson tank, or swishing the chemicals around. All this does is keep the exhausted developer on the central axis of the film, it doesn't shift it to be replaced by fresh developer. The two techniques used together is best, invert the tank to change the developer, then swish, or twiddle, to get rid of the air bubbles.

 

 

Steve

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[rpavich]

I'm sure it would help others if you could describe the technique that was bad?

 

But usually it is twiddling the stick in a Paterson tank, or swishing the chemicals around. All this does is keep the exhausted developer on the central axis of the film, it doesn't shift it to be replaced by fresh developer. The two techniques used together is best, invert the tank to change the developer, then swish, or twiddle, to get rid of the air bubbles.

 

 

Steve

 You are right Steve, it happened when I agitated slowly and not very vigorously. It also happened when I use my Rhonda next tank which I guess would be a lot like the Twitley stick.  I had heard that when you over agitate you get lots of grain so I never wanted to do that very hard but I guess I was way too gentle. 

 

 This is the YouTube video that I saw 

Edited November 1, 2015 by rpavich

[250swb]

As he says in the video, we all have our own techniques, but he is very vigorous to my mind. You only need to invert it gently a couple of times then swish the chemicals around to get rid of air bubbles. Shaking the tank up and down against the palm of his hand seems to me like a method of producing air bubbles because some developers froth more than others.

 

But here is the thing, if his tank is brim full of developer his technique may be the best he can manage because he would have a fundamental problem, if you invert a brim full tank the chemical solution at the bottom does mix and change ends, it stays where it is, just the same as inverting a full bottle of any liquid. So you need very vigorous agitation to try to get the developer flowing inside the tank. With any similar tank, Paterson etc., it is a good idea to always use a size bigger than you need, and never fill it brim full of developer, then you can invert it more gently (avoiding surge streaks and froth) and banging it on the bench or against the palm of the hand to remove air bubbles can be replaced with a swish (or a twiddle) because you haven't created so many bubbles in the first place.

 

 

Steve

Edited November 2, 2015 by 250swb

[M.Hilo]

You seem to be going from one extreme to another.

 

Your agitation has probably been too little. The agitation of the youtube fellow is way too much.

 

Gentle but decisive agitation is needed. You better shoot a test film and increase your agitation. Knocking and shaking as hard as he does will lead to a much higher contrast. So yes, the light sides will not be there anymore, but you risk to lose detail in the dark parts and not get detail in the light parts.

 

Mosts tanks you can open the top to let the airbubbles out. Again, slight knocking the tank against your bassin or table will do the trick. Then you put back on the top . . .

[rpavich]

You seem to be going from one extreme to another.

 

Your agitation has probably been too little. The agitation of the youtube fellow is way too much.

 

Gentle but decisive agitation is needed. You better shoot a test film and increase your agitation. Knocking and shaking as hard as he does will lead to a much higher contrast. So yes, the light sides will not be there anymore, but you risk to lose detail in the dark parts and not get detail in the light parts.

 

Mosts tanks you can open the top to let the airbubbles out. Again, slight knocking the tank against your bassin or table will do the trick. Then you put back on the top . . .

 

Yes...he's very vigorous and I'm not "quite" that far but what I am doing now (very vigorous without his palm slamming) works for me now. No issues, no light spots, no specs no streaking...nothing except perfectly exposed negs without lost details.

 

 

As he says in the video, we all have our own techniques, but he is very vigorous to my mind. You only need to invert it gently a couple of times then swish the chemicals around to get rid of air bubbles. Shaking the tank up and down against the palm of his hand seems to me like a method of producing air bubbles because some developers froth more than others.

 

But here is the thing, if his tank is brim full of developer his technique may be the best he can manage because he would have a fundamental problem, if you invert a brim full tank the chemical solution at the bottom does mix and change ends, it stays where it is, just the same as inverting a full bottle of any liquid. So you need very vigorous agitation to try to get the developer flowing inside the tank. With any similar tank, Paterson etc., it is a good idea to always use a size bigger than you need, and never fill it brim full of developer, then you can invert it more gently (avoiding surge streaks and froth) and banging it on the bench or against the palm of the hand to remove air bubbles can be replaced with a swish (or a twiddle) because you haven't created so many bubbles in the first place.

 

 

Steve

Well...I can't say why or whatever but I can say that I got more vigorous with my agitation and 4 rolls now have come out perfectly...I'm not going to over think it...

[TomB_tx]

Advertisement (gone after registration)

I've always used Nikor stainless tanks, filled to just immerse they'll reel, with 3 gentle inversions every minute, rotating the tank partially between each inversion, and rapping the tank on the counter when setting it back down to dislodge bubbles. In past decades this gave good results with UFG and Acufine developers. I've done the same after starting up the past few years, using Ilford and Rodinal developers, except now I generally use a 150 ml single reel tank. The air in the top of the tank causes good mixing in the inversion process. I'm too old to change habits now.

[tobey bilek]

Gentile agitation is best so as not to get surge marks.   Just another internet myth that gets propagated .   

 

Insufficient agitation does not replace the used developer across the whole of the negative resulting in banding and streaks.

 

hint-  fix take more agitation than developer and you will not hurt a thing.   The process goes to completion, no further.

[Keith (M)]

Three very gentle inversions over a period of ten seconds (once per minute - Rodinal 1:50) then bang the bottom of the tank against the base of my palm.  Has always worked for me!

Edited November 10, 2015 by Keith (M)