I use 25xx tanks on the roller base. A single 25xx tank states 270ml of chemical minimum but 300 gives better results. With the tank on its side enough chemical to to just reach the center column will be sufficient and more chemical will just increase the weight. And, yes the cap must be on the tank.So I have two questions... the first is what is the MAXIMUM liquid you can put into a tank when doing rotary processing? The minimums are stated on the tanks, but the maximiums are really just based on the practical amount that will go in before the liquid wants to all dump out as you roll it? I'm guessing the cap will be necessary to ensure it doesn't leak everywhere...
Jobo tanks require a 3 to 5 minute pre wash. With the tank upright pour the water in and fill the tank to the top. Prep the developer, Agitate the tank 2 or 3 inversions then pour out the water. The antihalation coating will come off and discolor the water, do not reuse this water. Pour the developer in holding the tank at a slight angle, put the cap on, lay the tank on the roller base and start rolling and timing the development.Second, what is the process for filling the tank to avoid development "high water" marks from the initial pour?
I always use the minimum amount of developer required for the film being processed even if it means using more than the minimum amount of chemical listed on the Jobo tank.Over time I moved away from minimal-chemistry rolling approach taken by JOBO-style machines. It contradicts some manufacturer's datasheets (minimum amount of developer per roll), it's not B&W friendly (B&W benefits from pausing), and its only advantage (cost) goes away if you replenish. So I switched to full-tank, inversion-based automated agitation for both color and B&W.
[EDIT] another hard-to-troubleshoot problem I had with rotation was occasional surge marks. They weren't consistent or overly visible, but every once in a while I would notice a few very faint marks on my scans, and then they would disappear for months. Kodak Gold was especially prone to this. There were quite a few threads I found on photrio on this also (without a definite cure). Moving away from alternating rotation solved that completely.
So looking at the literature (and the web as well), I don't actually see what a good procedure is for doing this when you aren't actually able to be rolling the film as you pour in the chems (as the CPP/CPE machines do).
All Jobo rotary processors require the tank filled upright and then installed horizontally in the processor. Unless you got the lift attached (which not all their processors take, and it was offered much later anyway).
Exactly same procedure you have to follow, when you roll the tank along a table edge or on a roller base.
Volumes then are same as on a processor.
The issue you refer to was approached by Jobo at their print drums with those beakers incorporated into the caps. No such was designed for the film tanks. Likely as such would beaker would take space otherwise employed by the reels and as Jobo did not see such fluid-level mark issue with films on reels.
In case you do not trust the design, fill the tank as for inversion processing, use a cap with lid and rotate it this way. However with such high fluid level you might get other issues, from lesser fluid flow along the reels.
And as long as you use no tempering bath, the advantage of rotational processing is just the saving of bath volume. Filling the tank completely and rolling it then makes no sense at all.
The only reason for "no prewash" with XTOL is because Kodak's testing was done that way. XTOL works fine with a prewash, but the times will be different. That straight from Dick and Sylvia many years ago (the inventors of XTOL). I always use a prewash, except for certain Ilford roll films when inversion agitating....I'm going to test a few developers and at least one of them (XTOL) specifically recommends not doing a prewash before the developer. I dont know what the reason is, but I'll look into that a little...
I own CPE-2+, CPA-2 and CPP-2 processors, all purchased new, as well as a wide variety of Jobo tanks (1500 series and 2500 series) and drums. I process sheet film in Expert drums, and wouldn't do it any other way....I could just do them all inversion anyway). I'm not wedded to rotary, but I would prefer to not be dumping excessinve chemicals in the drain if I can help it...
Are you doing extended presoak to warm tank for color processing? 3-5 minutes, while it shouldn't hurt anything, seems a bit long. The sensitizing dye on color film is why I do a 100°F presoak on C-41, it's amazing how much color comes out in a single 60 second soak. I've concured the purple stuff in T-grain Kodak films by using a good fresh rapid fixer, followed by Kodak Hypo clearing agent, 2 minutes (this really helps with the purple). Then a nice wash. I keep wash at minimum of 68-70°FI use 25xx tanks on the roller base. A single 25xx tank states 270ml of chemical minimum but 300 gives better results. With the tank on its side enough chemical to to just reach the center column will be sufficient and more chemical will just increase the weight. And, yes the cap must be on the tank.
Jobo tanks require a 3 to 5 minute pre wash. With the tank upright pour the water in and fill the tank to the top. Prep the developer, Agitate the tank 2 or 3 inversions then pour out the water. The antihalation coating will come off and discolor the water, do not reuse this water. Pour the developer in holding the tank at a slight angle, put the cap on, lay the tank on the roller base and start rolling and timing the development.
Reversing the direction of the rotation is necessary to prevent streaking. Rotation should be equal in each direction for the development time. I go from fingertip to palm of hand, switching hands to keep a constant rotation then I switch to palm of hand to fingertip turning the tank in the opposite direction every minute. A partial minute in one direction will not affect outcome. The alternative is to stop, pick the tank up, and lay it back down with the lid end on the opposite side of the roller base.
The 10 to 15 seconds it takes to pour the developer in, put the cap on, and lay the tank on its side is 3% to 5% of a 5 minute development time and should not create noticeable difference in development and on longer times it will not. Fill the tank with stop bath, wash water, fixer as rotation is not necessary for these steps but can be used if desired.
I develop both 4x5 sheet film and 120 roll film in my 25xx tanks.
I recently bought a Jobo 1500 large kit from B&H. It's like a big box full of goodies for 200 USD. Cheap these days, you get a bunch of stuff, I was surprised how nice the roller base is. I would get tired of rolling for long film development but it is a nice device.OK, good enough to convince me on this. I think it's clear that I don't need to fret the filling marks at all.
I'm going to test a few developers and at least one of them (XTOL) specifically recommends not doing a prewash before the developer. I dont know what the reason is, but I'll look into that a little.
The minimum amount of stock developer solution (per the developer spec sheets) is an issue and I'm not concerned about going over the minimum solution values on the tanks at all, but I just wanted to figure out how much I could go over without causing issues. For example as I read it, XTOL wants 100ml of stock solution per roll of film, so if I wanted to do straight, I would need at least 600ml in a 1526 tank (three 120 roll spools, six total rolls), which meets the minimum fill numbers from Jobo (570ml). If I wanted to do 1:1, I'd need 1200ml of developer. At that point, I might as well just do inversion development, because I am just about filling the tank up, and that alows me to get a little longer development time and a bit higher acutance in the negatives due to the much less constant motion of the developer fluid.
That issue isn't really a concern for Rodinal or HC110 I don't think... it is so concentrated that I'll be able to do the developing at a reasonable dilution and not have it be a full tank (or maybe it will be a full tank, but that'll be fine as I could just do them all inversion anyway). I'm not wedded to rotary, but I would prefer to not be dumping excessinve chemicals in the drain if I can help it. The XTOL is specifically on my list because of the relatively lower risk and concern of the compunds in it.
Yes, that's exactly what I am thinking... After doing the math on this, with 1500 tanks, there doesn't seem to be any point to doing rotary.There's no way it can be described as an "excessive" quantity discharged to sewerage. I strongly suggest you embark on your medium format adventure without the unnecessary complication of rotary processing film.
JOBO system is after all designed for rotary processors using minimum volumes.
I use 25xx tanks on the roller base. A single 25xx tank states 270ml of chemical minimum but 300 gives better results. With the tank on its side enough chemical to to just reach the center column will be sufficient and more chemical will just increase the weight. And, yes the cap must be on the tank.
Jobo tanks require a 3 to 5 minute pre wash. With the tank upright pour the water in and fill the tank to the top. Prep the developer, Agitate the tank 2 or 3 inversions then pour out the water. The antihalation coating will come off and discolor the water, do not reuse this water. Pour the developer in holding the tank at a slight angle, put the cap on, lay the tank on the roller base and start rolling and timing the development.
Reversing the direction of the rotation is necessary to prevent streaking. Rotation should be equal in each direction for the development time. I go from fingertip to palm of hand, switching hands to keep a constant rotation then I switch to palm of hand to fingertip turning the tank in the opposite direction every minute. A partial minute in one direction will not affect outcome. The alternative is to stop, pick the tank up, and lay it back down with the lid end on the opposite side of the roller base.
The 10 to 15 seconds it takes to pour the developer in, put the cap on, and lay the tank on its side is 3% to 5% of a 5 minute development time and should not create noticeable difference in development and on longer times it will not. Fill the tank with stop bath, wash water, fixer as rotation is not necessary for these steps but can be used if desired.
I develop both 4x5 sheet film and 120 roll film in my 25xx tanks.
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