Agitation : Circular Or Back& Forth?

[DF]

I do a continuous circle 3 or so times when "agitating" film in the canister, but it seems most do the back & forth movement. Is one style better than the other? When I say "circular" I don't mean with the direction of the film, I'm turning it upside down but in a continuous direction.

 

[wiltw]

My own preference is for 'inversion' agitation. Turn the container upside-down, then rightside-up at a rate of about 1 sec. per cycle. so that if observing a clock with second hand on it, the developing tank is upside-down on the 1-3-5 counts and the tank is rightside up on the 2-4-6 counts, with 5 cycles in 5 seconds. (Alternative to inversion agitation is imply to slide the tank back-and-forth sideway across a 10" path....Kodak documentation mentions both types of tank agitation.) Agitate every 30 seconds...5 second agitation cycle followed by 25 seconds of tank sitting.

Agitation should not cause regular 'currents'...it should be somewhat more random acting

 

[MattKing]

Grab the top of the tank with one hand and the bottom of the tank with the other.
Now invert the tank by moving your bottom hand over the top. As you do so, your hands will also naturally rotate it in one direction.
Now right the tank and then invert it the other way, so that the rotation is in the opposite direction.
Finally, right the tank again.
You will have combined both inversion and rotational agitation.
You don't need two hands to do this, but the demonstration with two hands will show you what it looks like.

 

[Theo Sulphate]

Back and forth!!!

My one failure (total loss of negatives) happened when I used a single direction - the resulting currents caused the film to come out of the spool rails and stick to itself during development.

Of course this would happen with my irreplaceable images: a lecture given by Donald Knuth.

 

[RalphLambrecht]

I do a continuous circle 3 or so times when "agitating" film in the canister, but it seems most do the back & forth movement. Is one style better than the other? When I say "circular" I don't mean with the direction of the film, I'm turning it upside down but in a continuous direction.

I prefer the continious rotation of the Jobo processor but don't think it matters much as long as you get fresh developer to the emulsion somehow.

 

[jimjm]

Here's one area where you're going to get lots of differing opinions. Ultimately, the best way for you is one that will give the best results with even development and no surge marks.

My method is 2-3 inversions within 5 seconds, with half a rotation as I invert the tank. Not a continuous rotation as you do, just invert then back upright as I randomly rotate the tank CW or CCW. I try to be relatively gentle with the motion - not too jerky and don't shake the tank. In the past I found that agitating too aggressively caused surge marks, especially with shorter development times where the developer is much more "active". Some developer/film combinations call for 5 sec of agitation every 30 sec, others for 5 sec every minute.

 

[tedr1]

The data sheets for Ilford roll films call for inversions.

 

[DF]

I guess what I'm trying to say is that I "invert" but continuously in the same direction - not upside down - then right side up. The 1st 6 minutes of, say, FP4, I'll do them moving forward, then the last 5 minutes backward. Works fine and seems a lot easier, more efficient.

 

[Leigh B]

I prefer the continious rotation of the Jobo processor but don't think it matters much as long as you get fresh developer to the emulsion somehow.

Exactly.

The purpose of agitation is to replace exhausted developer with fresh developer.

Any gentle movement of the liquid will accomplish this. Inversion is probably best since it causes the greatest movement of the liquid, but I doubt it matters much.

- Leigh

 

[silveror0]

Right, Lee. Your key word is GENTLE, as we're not shaking cocktails here and avoid generating foam.

 

[bvy]

I guess what I'm trying to say is that I "invert" but continuously in the same direction - not upside down - then right side up. The 1st 6 minutes of, say, FP4, I'll do them moving forward, then the last 5 minutes backward. Works fine and seems a lot easier, more efficient.

I'm not sure it's inversion if you're not turning the tank upside-down then back. There's also figure-8 agitation which involves moving the tank in a figure-8 pattern with the tank always upright. It should be fairly vigorous (not ridiculously so). Inversion is probably best for really mixing things up and getting fresh developer to the film, but it can easily aerate the developer and introduce foam (even when you think you're being gentle). Figure-8 is a nice alternative. It can be done on or off of a work surface.

 

[silveror0]

It's also worth mentioning that when I used to use Nikor tanks and reels with inversion agitation, I first found the best fitting caps on the tanks and marked them as pairs to minimize the leakage; when inverting the tanks I'd place a thick dry towel over the caps/tanks to keep the heat of my hands from raising the temp of the developer and absorb any minor leakage that seemed inevitable.

 

[Ronald Moravec]

follow post #2. 50 years that way and never had a problem .

Film in JOBO processor is supposed to be c/wise & then counter c/wise. About 1 .33 turns each way. Without machine, follow #2.

You can also use a two reel tank with two reels, film on the bottom only. Use 8 oz solution only. agitate by inversion (forget the gentle crap), You can use the same set up and roll 1.5 turns one way, then back. Upright and wait until next cycle. Basically you have simulated machine process with stationery wait.

All these work.

 

[removed account4]

figure-8's and twisting it

 

[bdial]

Based on all the threads regarding agitation and problems with it, it seems to turn out to be a very personal thing.
As Leigh suggested, what works for you is the correct way. If it's not working for you, evidenced by unevenness or surge marks, make a change.
For roll films, I use stainless tanks, and mostly invert in just one direction, clockwise, with my right hand. But occasionally do it the other way, if I'm adjusting the timer or pouring the next solution with my right hand.
For twirl-sticks with plastic tanks I usually go back and forth gently.

 

[Luckless]

Don't forget the figure-eight pattern for non-inversion options. That seems popular from what I've seen.


Personally I stick with the inversion method for my paterson tanks, giving it a 1/3 twist every turn. (The little notches on the bottom of the tank make fairly natural points to put your fingers I find.) I also take the inversion fairly gentle. My goal has been to 'gently pour the solution to the far side of the tank', rather than sloshing it around or anything.

 

[laser]

Don't lose sight of the objectives:
1. replace spent chemicals at the film's surface

2. do so in a random fashion so a flow pattern is not created

The best way to see if your technique is adequate is to uniformly expose a roll that will produce a density of about 1 (10% transmission). Easy to determine approximate density by printing for 1x and 10x if you don't have densitometer. Then print the negative in a typical fashion on to typical paper. If there is a visible pattern in the print you need to increase the vigor and randomness.

For roll film, stainless steel tanks that can be inverted are best. Through the years several agitation techniques by multiple users have been studied.
My experience: Bang the processing tank on a firm surface to dislodge air bells, don't be gentle. First 30 sec vigorous and random agitation. Then 5 inversions/5 sec starting every 30 seconds works for me. I give a slight twist with each inversion. To maintain temperature I set the tank in water bath for the remaining 25 seconds in each cycle.

 

[Gerald C Koch]

It's also worth mentioning that when I used to use Nikor tanks and reels with inversion agitation, I first found the best fitting caps on the tanks and marked them as pairs to minimize the leakage; when inverting the tanks I'd place a thick dry towel over the caps/tanks to keep the heat of my hands from raising the temp of the developer and absorb any minor leakage that seemed inevitable.

With the Nikor tanks the metal caps were matched to the lids when the tank left the factory. If you have more than one tank it is best to mark the three pieces so that things fit properly as intended. Mismated parts will leak.

When we think of mass production we tend to think uniformity in part size. This assumption really may not be valid. I learned this from a friend who worked on his Porsche. The cylinders had one to three dots on them to mark whether each one was under, over, or standard size. The openings in the engine block were also marked. Mismatch things and you lost a lot of compression.

 

[AgX]

This whole thread with its wording is beyond my spacial imagination.

 

[LAG]

Is one style better than the other?

No

This whole thread with its wording is beyond my spacial imagination.

Yes

 

[adamblackmanphotocom]

I would like to add that the look that you are aiming for is relevant to how you agitate. If you want heavy grain and shadow, increase agitation speed. to increased grey scale agitate less and increase developing time. It's all about taking notes on what you did how it applied. I use Microsoft excel as a data log just to have an ongoing reference. By using date/film type/ISO/Developer/Time/FIX/ and lastly agitation/ I've come up with my go to's for various scenarios. it also helps if you know what kind of light you shot in i.e. Bright sunlight or soft light. I find HC-110 to be a great developer that can be molded by changing dilution and agitation.

After doing this experimentally I've learned what works for my general style. My Mentor shot HP5 at 1600 exclusively and used little jiggling motions for his development every few minutes.... Super unorthodox. Great results for him.... and to each there own.
Cheers
adamblackmanphoto.com

 

[Pat Erson]

For me what works best is a "rollercoaster" type of agitation : up down right left!

BUT imagine a rollercoaster for senior citizens where every wagon would move very gently.

 

[Bob Carnie]

Grab the top of the tank with one hand and the bottom of the tank with the other.
Now invert the tank by moving your bottom hand over the top. As you do so, your hands will also naturally rotate it in one direction.
Now right the tank and then invert it the other way, so that the rotation is in the opposite direction.
Finally, right the tank again.
You will have combined both inversion and rotational agitation.
You don't need two hands to do this, but the demonstration with two hands will show you what it looks like.

Plus one on this method ,

 

[Gerald C Koch]

The following document describes Kodak's recommended agitation method on page 4.

http://wwwuk.kodak.com/global/en/professional/support/techPubs/f4017/f4017.pdf

 

[Tim Stapp]

when I use the hand inversion method, I've always rotated the tank during inversions so that the direction of rotation tightened the lid. I've since graduated to the JOBO.