Inversion or rotation

frank · Sep 4, 2014

It was pointed out that rotational agitation results in film in the larger spirals moving faster through the developer than the film in the inner spirals.

I use rotational agitation and haven't seen any evidence of uneven development because of this. Has anyone? Why would Patterson provide a twirler handle if it were so?

Inversion agitation, when I imagine what happens in the tank, isn't providing even flow of developer over the film either, given the air trapped inside.

So, how do you guys agitate, and why?

(I don't think how you do it is important in that there isn't a correct and incorrect way, as long as what you do is working for you.)

pdeeh · Sep 4, 2014

Mason: "In any method of agitation it is imperative not to get streamlined flow over the emulsion surface. The flow of the developer over the emulsion surface must be as random as possible"

[apart from special cases like stand, of course]

So I do a sort of soft maraca-shuffle

timor · Sep 4, 2014

Inversion agitation is an inheritance from times of low contrast films and tanks like the steel tank. Modern films require much less agitation. I am using rotational agitation all my life and have same experience like you. However there are films which do not like it (IMO and experience) like Delta 400 which is too bad as it is my future replacement for TMY (in the case... of course ).

Frank, I like your words on your home page. My thumbs up.

timor · Sep 4, 2014

pdeeh said:
Mason: "In any method of agitation it is imperative not to get streamlined flow over the emulsion surface. The flow of the developer over the emulsion surface must be as random as possible"

[apart from special cases like stand, of course]

So I do a sort of soft maraca-shuffle

Of course, no one talks of swirling in one direction only

Old-N-Feeble · Sep 4, 2014

My development times were always between 11 and 16 minutes. Invert once, rotate 180 degrees and invert again then two taps then swirl left one second then swirl right one second then tap again every thirty seconds. Did this for two minutes then went to every minute. Development was always very even.

DREW WILEY · Sep 4, 2014

Other than sheet film, I use little Jobo hand inversion tanks for everything, with exactly the same pattern for every single black and white film.
The time or specific developer might change, but my agitation pattern never does. It's basically the same they show in the old Kodak manuals.
Every 30 secs I gently invert twice, once one way, once the other. No problems. Absolutely no difference between new films and old-school ones in this respect, between fast or slow, allegedly high contrast or low.

John Bragg · Sep 4, 2014

Always invertion for me. With 15 seconds continuous, then only 2 invertions every 4 mins thereafter. Kind of minimalist/semistand thing. It works for me.

winger · Sep 4, 2014

When I've tried using a twister stick to do rotational agitation, the unevenness wasn't between the frames on the outer part of the spiral being different from those on the inner ones - it was across individual frames. The outer edges developed to be darker than the middles of the frames. This also happened more with shorter developer times, so film/dev combos that are 10 minutes may not see this as readily as those around 5-6 minutes (which is where mine was).
So I use inversion and try to keep the times longer.

cliveh · Sep 4, 2014

I just use inversion, but before I lost my twizzle stick I used both methods during development.

MattKing · Sep 4, 2014

frank said:
I use rotational agitation and haven't seen any evidence of uneven development because of this. Has anyone? Why would Patterson provide a twirler handle if it were so?

If you read the instructions packaged with Paterson Super System 4 tanks, you will note that they recommend using rotation only for the initial agitation, and inversion thereafter.

cjbecker · Sep 4, 2014

Inversion only, I have had bad results with rotation. I have switched to all metel tanks also.

bvy · Sep 4, 2014

MattKing said:
If you read the instructions packaged with Paterson Super System 4 tanks, you will note that they recommend using rotation only for the initial agitation, and inversion thereafter.

I missed that, but it happens to be exactly what I do. You can waste a good thirty seconds from the time you finish pouring the developer trying to get that cursed lid on. And since the initial agitation is allegedly the most critical, I quit trying. It's even more critical with C-41. With C-41 I twirl for thirty, put the lid on, then invert two times every fifteen.

Pioneer · Sep 4, 2014

I do both.

With the jobo tanks I use continual rotation on the rollers, either by hand or with the machine (for C-41.) I use the jobo tanks for single to multiple 120/220, 4x5 and multiple 135. I have never noticed any uneven development with this system. The machine reverses rotation every ten or so rotations and when I do it by hand I also reverse agitation though I typically run up to 30 rotations in each direction, though I am not particularly religious about this.

For single rolls of 135 I use a small Arista Premium one reel plastic tank and use inversion only. This method is also consistent but uses more chemistry than the jobo system does.

DannL. · Sep 5, 2014

For about 8 years I did continuous random agitation with roll film, and only recently (8 mos.) switched to semi-stand (w/multiple inversions at regular intervals). I really can't see that it makes much of a difference in my prints. Sheet films are developed in drums on a roller base. As I only just recently purchased a Jobo processor, it is rotary with direction change intervals and speed adjustments. But, I haven't used enough sheet film recently to warrant filling it up with water. Plates are developed individually in trays with a homemade tool that allows me to run the plate through (the drag method), without putting my fingies in the chemicals.

Joel_L · Sep 5, 2014

I have used inversion, twizzle stick, and rotary ( Jobo and uniroller ) and have never had any issues with development. I have done 35mm and 6x7 in all of them. Now days, all color ( negative and E-6 ) goes through the Jobo. I will do B&W in what ever is convenient at the time, I still like using the unidrum on its roller base for B&W.

Joel

Inversion or rotation

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