You can even run into problems with uneven development when you use inversion agitation, if you always agitate in a very constrained, exactly duplicated way.
For that reason I always tell people who are new to this to both invert and rotate the development tanks - you want the developer to tumble ang cavitate through the film. You should be able to hear it gurgle.
It is possible to achieve good results with a less energetic approach, but it takes a lot of attention and care toward adding a reasonable amount of chaos.
Ugh... That's me. I was aiming for consistency.
Understood. Shake it like you're making a margarita!
EDIT: Kidding aside. What I normally do is I rotate the tank along one axis when turning it upside down, and then along a perpendicular axis when turning it right-side up. No idea if this provides sufficient randomness, but perhaps it's close enough to the tumbling you describe.
The problem that @mshchem refers to is that of laminar flow, which can be summarized/simplified as a liquid flowing relatively slowly across a surface, with the liquid forming more or less discrete 'layers' that don't mix (much).
Never thought of processing paper on a tube. I might give it a try. --- Still not gonna buy a Jobo, but as @GregY said, you can just roll the tube on the counter.
At this point I've got the cost of chemicals for the darkroom to a level that I'm comfortable, but if I can lower that cost a bit more without a huge hassle, why not. Problem is, of course, you can't see the image on the paper appear, so you can't make a spontaneous decision to shorten or lengthen development.
As I recall it from 1st year Physics so long ago, the study of thermodynamics and fluid flows was a far from simple exploration!
Never thought of processing paper on a tube. I might give it a try.
Problem is, of course, you can't see the image on the paper appear, so you can't make a spontaneous decision to shorten or lengthen development.
From the link: "One gentle flip per minute is optimal for B&W." I wonder what the author's stand is with stand development. Sounds like someone found the best way for themself and believes in it.
I tray-developed for a couple decades, and still do for 11x14. For the last couple of decades or so, everything smaller than 11x14 goes into Jobo Expert Drums and rotated at 15 rpm...that's how fast my Unicolor motor base can go. I contact print in alt processes with no burning/dodging...so any uneveness in processing would be undesirable. So far so good. But I am always expanding the DR of the film, which probably uses the advantages of the continous agitation (instead of continous agitation fighting attempts to contract the DR).
Palms, Spring, Death Valley, 8x10 pt/pd print.
As I have motor base and tubes I have used drums for black and white, currently I am using trays, but, drums use a bit less chemistry but I could mix up just enough chemistry for a a couple of 8X10s. I've used Clayton and other liquid concentrates, with Clayton the recommended dilution is 1:9, I would mix 1/2 oz concentrate with 4 1/2 water for working per 8X10. Standard stop and fix, a bit less than developer 3 oz all dumped, 8 water rinse, followed by 3 oz Perma wash then remove and wash in a tray or print washer. For larger printing session having to wash the drums between prints is just too much a hassle so I revert to trays. I also like watching the print come up in the developer.Never thought of processing paper on a tube. I might give it a try. --- Still not gonna buy a Jobo, but as @GregY said, you can just roll the tube on the counter.
At this point I've got the cost of chemicals for the darkroom to a level that I'm comfortable, but if I can lower that cost a bit more without a huge hassle, why not. Problem is, of course, you can't see the image on the paper appear, so you can't make a spontaneous decision to shorten or lengthen development.
The noise they make can get quite horrendous after awhile. I have a Beseler motor base that also rocks the tubes as they spin, but have not tired it yet. The Drums can want to walk off the motor base sometimes, so one can counter that. I do not feel very comfortable leaving them long while turning without adult supervision.I can't believe you use Unicolor roller with Expert drums but makes sense. It would "work". I threw mine out when I couldn't get Cibachrome anymore.
If you want a good, repeatable way to add appropriate amount of chaos to your agitation, try this:
1)hold the developing tank vertically, with your palms - one hand on the bottom, and one hand on the top;
2) turn the tank upside down in one direction - e.g. clockwise - by rotating your hands and wrists, so the bottom hand ends up on the top and the top hand ends up on the bottom - note how the natural action of your wrists imparts both inversion and rotation to the tank;
3) repeat in reverse what you just did in order to move the hands back to their original position, again imparting both inversion and rotation;
4) do the same again, except start out in the opposite direction - counter-clockwise instead of clockwise; and finally
5) return the tank to vertical.
In total, that is two inversions. To someone watching you, it will look like you were driving a car/steering.
It is far harder to describe than it is to do it.
It is a good idea to wear gloves - perhaps a darkroom apron too.
The noise they make can get quite horrendous after awhile. I have a Beseler motor base that also rocks the tubes as they spin, but have not tired it yet. The Drums can want to walk off the motor base sometimes, so one can counter that. I do not feel very comfortable leaving them long while turning without adult supervision.
Before the Drums I tray developed and prolonged the agony by doing them one at a time...although I eventually used two developing trays in a larger tray and just agitate the larger tray.
I have three 3005 drums -- during workshops I can load up all three (15 sheets of 8x10) and process one drum at a time (pre-soak, Dev, stop, fix, partial wash), then start a new drum while finishing washing the first batch. Goes pretty smoothly.
When I use tubes, I standardize on a development time toward the long end of the recommended range.
Too much agitation leads to foaming, bubble marks, and surge marks. Find a happy medium.
Well maybe not if you repeat your cycle of agitation in the same way each time . I base this on certain replies I receivedEDIT: Kidding aside. What I normally do is I rotate the tank along one axis when turning it upside down, and then along a perpendicular axis when turning it right-side up. No idea if this provides sufficient randomness, but perhaps it's close enough to the tumbling you describe.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?