Jobo Processing

[Richard White]

Response to Bob Carnie

With regard to processing 4 x 5 shhet film in a Jobo. I am not using distilled water. I use rain water. This was not an issue before. It's confusing. I also use the black inserts. Have hand processed film in the Jobo tank and no problems. It is obviously the movement of the drum.

The added density is along the long side of the film which would be in the direction of the water flow. The middle and inside films seem not to be affected. Obvious solution don't load film on the outside or hand process, but....

Anyway I will keep at it. If you or anyone can offer any other hopeful solution then I would be grateful. I didn't tell you that I live in Australia. This in itself could be the cause.

Cheers from Down Under, Richard

[bob carnie]

Hi Richard

Try the distilled water, just for peace of mind, I do believe it could be laminar flow problems, distilled water allows the chemicals to flow onto the film easier.
Manual agitation is definately an answer as you can disrupt the flow pattern.
good luck

[Kirk Keyes]

Bob - could you explain by what mechanism distilled water allows chemicals to flow onto the film better than non-distilled water?

[bob carnie]

Kirk
My understanding is that the minerals in regualar water cause a friction that does not allow the chemicals to flow freely over the film, as it rotates, wheras distilled water is free of minerals and allows the developer to move faster over the film.
I have found this to be critical in the first few rotations of film development. We have tried both over the years and distilled water has always been cleaner.

[paulr]

The important thing about distilled water is that we know what's in it: water.
Tap water, rain water, well water, bottled water, etc., can have all kinds of things in them. Just a few of the variables are pH, mineral content, chlorine content, fluoride content.

As an example of the consequences, effective washing times vary enormously from one tap water source to another; researchers have their theories but no one really knows why.

The idea of minerals in the water causing friction sounds a bit contrived--i'm more likely to believe it has to do with surface tension-- but then again, I don't know, and I'll bet no one's spent the research money to find out.

We're in the world of empirical knowledge with this stuff. The best we can do is try something, systematically if we have the patience, and then share it with friends, so they don't have to waste a day of their lives too!

[paulr]

oh, another thing ... have you talked to the tech guys at Jobo? it's been a while, but they were always incredibly helpful, and they really knew what they were talking about.

and a few things that have helped me get even negs with a jobo drum:
-an alkaline presoak. just a bit of sodium metaborate in the presoak water, and presoak for at least a couple of minutes.
-make sure the machine reverses before flow patterns get a chance to develop (i think the jobo guys recommend reversing every five seconds)
-consider your developer. developers that encourage edge effects (from bromide sensitivity) also tend pose evenness challenges.

[Nick_3536]

The minute you add anything to the distilled water it's not just water anymore. Add developer. Breath on it. whatever. It changes. Put me in the confused camp on distilled water.

[bob carnie]

Hi Paulr
I have never considerd a alkaline presoak, I will try it this week.
I use a ALT2300 and I am not sure I can program the rotations to every five seconds. it is interesting though you mentioned this as I do believe this is the problem Richard is having . We let the machine rotate once then we manually take off the drum and and give a complete inversion as if working with stainless steel tanks. We then put the drum back on machine, rotate again , then take off again complete inversion, we do this three times in the first 45 seconds of development. This method completely eliminated a problem we were having with 120 film in the jobo.

Regarding distilled water vs regular tap water (not softened) I suggest a simple test.
(to keep it ok for the large format people use a 6x9 back on your large camera)

Expose two 120rolls of trix @ISo200 , identical NUETRAL background
Develop on a rotary processor, using Hutchings PMK formula, two different runs (normal)
first film use tap water
second film use distilled water
Lay the two films on a light table and you will find a minus density lines on both sides of the film running approx 1mm into the image area in the direction of the rotation of the Jobo. It will be present on the film that was run in tap water, the film ran in distilled will not have the minus density lines.
I have tried this many times to verify this problem.... ( It may be the ph of the water in Toronto, but I know this problem exists)

Richard elimatate these two problem areas and I believe you will be closer to correcting the lines you described

[Steve Feldman]

Hi ya'll. (I'm not from the South - just like sayin' that).

I've been processing B & W in L.A. for the past 20 years. 35mm, 120/220, & 4x5 films in a Unicolor Drum. Always with tap water (OK for film/paper processing - don't drink the stuff). I used to get processing streaks, pin holes and air bells. My cure? One drop of Photo Flo in the pre-soak AND in the developer. I'm sure that this breaks the suface tension and stops streaking. It just makes the liquids, well, er, ah, . . . . . flow.

Works for me.

Your mileage may vary.

[Nick_3536]

Toronto water is full of calcium carbonate with a pH of about 7.5. I still don't understand. Once you've added all the stuff in the developer is the mineral level in the water really that important?

[paulr]

Yes, of course when you add other stuff to the water it isn't distilled anymore.
The point is, you KNOW what you're putting in there. When the water isn't distilled you don't know what's there.

Or in some cases you do know, and you know it's bad. For example, chlorine kills nelson gold toner. If you use distilled water when you mix it, it can last for hundreds of negatives with replenishment. if you use chlorinated tap water it will become useless very quickly.

In the case of wash water, the effect of minerals is unpredictable. This is why you have to test your process for residual hypo whenever you move. I knew someone who was able to clear their negatives with a 40 minute wash in one place; after moving to a different state his wash time increased to an hour and a half. Every other part of the process stayed the same. Mineral content was significantly different in both places, but there's no hard science on the process of what's going on.

There's no proven reason to use distilled water to mix most developers; but there's no proven reason not to. I choose to do it because there are already so many weird variables when it comes to developing film; distilled water seems like a cheap way to eliminate a few of them.

I've never heard a reason to mix stop, fix, hypoclear, or anything else with distilled. But many toners require it, and it's not a bad idea with developers. Especially if you live in a place with weird water.

[Nick_3536]

Here you need to mix photo-flo or I guess stabilzer with distilled or you'll have spots.

I thought Kodak found sea water washed quickest.

I haven't checked lately but last time I did the water quality standards for Kodak's colour chemicals allowed quite a bit of crap. Commerically mixed products are going to have sequestering agents added. I'd expect any published formula that needs distilled water to call for it. Even the most basic water filter will remove cholrine.

The other thing is he isn't having a total developer failure. He's seeing increased/decreased developer action on part of the negative. IIRC Jobo admitted the 120 reels can have problems around the edges but it's supposed to be outside the image area?

The only thing that makes any sense to me is he isn't using enough developer and the inside sheets aren't getting enough developer. Or maybe the drum isn't level?

[paulr]

the story about sea water washing is actually how hypo clear got invented. someone noticed that seawater was many times as fast as plain water; it turned out that some of the salts exchanged ions with the ions that make up thiosulfate molecules, make the sulphur compounds much more water soluble. hypo clearing agents are just a more refined way of accomplishing the same thing.

[bob carnie]

hello folks

The following is from THE FILM DEVELOPING COOKBOOK STEPHEN G. ANCHELL BILL TROOP
PAGE 29.
I hope this blurb helps this discussion

Water is a crucial, often overlooked , constituent part of all photographic formuals. If you do not think so , try developing and fixing your next roll of film in dry chemicals!
In general, the wide variety of impurities found in water are present in such small quantities that they have little effect on photographic solutions. However, bearing in mind that the mineral content of tap water can change from one day to the next it is always safer to use distilled water for mixing developers. Minute impurities in water are especially problematic with pyro and catechol. Distilled water is the cheapest way ensure quality negatives.
With most tap water, a viable alternative is to boil it for three minutes and let stand overnight. Boiling removes gases. Standing overnight allows particulate matter to precipitate out. Decant carefully.
Generally, stop baths and fixers are not as sensitive to water variations as developers. If a problem does appear, use distilled water.
Filters can help protect films from water impurities. If a filter is not available use several layers of and additive-free paper towel, such as Bounty Microwave, or a coffee filter. Water with any visible colour should not be used in photographic processing.
Softened water should not be used in developers. If it cannot be avoided, use distilled water instead.
Sea water cannot be used for mixing most photographic solutions. Sea water can be used as a hypo clearing agent after fixing with acid hypo solutions, but a final rinse in fresh water is obligatory.

Wheww Both Mr Anchell and Mr Troop really seem to know their stuff when it comes to film processing and formulas. I have two of their books and I think they are great.

[Kirk Keyes]

Bob - that's an interesting theory about "friction" causing these effects. Perhaps you mean surface tension not allowing the film to wet evenly when the liquid is first poured into the drum? The suggestion about adding photo-flow to the solutions is one that can overcome issues with surface tension, but I think it is usually not recommended. A presoak of simply adding water and then running the drum for 5 minute may help with this, as it will remove any surface tension issues since the film will be wet when the developer is added.

But Nick's right that the vast majority photographic chemicals are designed to work well with a wide range of water of varying quality. Generally, the rule of thumb is if your water is suitable for drinking, it's suitable for photography.

On the subject of chlorine, a basic water filter (that is, one for particulate only) will not remove chlorine. I believe that municipal waters in Canada have a limit for residual chlorine of 0.1 ppm (parts per million of mg/L) and that in the USA the levels are typically around 1 ppm. The chlorine in your water, much like the dissolved oxygen in your water (which will typically be somewhere around 10 ppm and comes from the air) will react with any sulfite in your developer and be neutralized. And at 10-11 mg/L of these two oxidizers, they will not consume much sulfite in that process.

While paulr's arguement that deionized water is better because you know what you are starting with, for those of us on municipal water supplies, we can ask our water provider what is in our water and find out for ourselves - I'm in Portland, OR, and our water is very low in dissovled minerals and should not be a source of problems with photographic uses. Learn about your water supply and be better informed for decisions like this. Your water supplier will have the answers to questions on pH, mineral content, chlorine content, fluoride content, and a whole lot more.

Finally, I'd suggest that Richard email Jobo themselves and ask for suggestions - as I'm sure they've seen every issue by now and they probably have several suggestions towards solving this issue.

[bob carnie]

Kirk
Basically that is how I understand it. Friction could be surface tension . We went through a series of test recently to correct a problem that crept into our lives. We called Jobo many times and tried all their suggestions , in the end we ran over 35 runs with every concievable variation that can be applied to a Alt2300 Jobo. A very interesting observation was brought up by a John Callow from Detroit area was to load the film in emulsion out . He suggested that the chemicals would attack the emulsion much quicker , and not pool inside the rolls as the Jobo rotated, we have not tried this yet as it may be difficult to learn well.
As stated earlier in posts we solved this problem by manually agitating the film in the very beginning stages of development. We still do this to this day. This problem only showed up on 120 film and would present itself as two wide road rutts, minus density on the film running the length of the rotation. The worst case would be the inside roll when you run two 120rolls on the reel.
This was not mentioned by Jobo as a fix, obviously as it goes in the face of rotary processing. We actually stopped production of 120 film in the Jobo and went back to stainless steel manual development. This problem funny enough did not occur with Pyro, only d76, tmax, microphen, hc110, rodinal.
For anyone producing film to exacting standards these small marks or patterns can drive anyone around the bend. Our livelyhood depends upon clean well developed film. Even though I think the Jobo system is fantastic, buyer beware it does have some very wierd problems that can give one migranes solving.

[Kirk Keyes]

Bob - It sounds to me like the developer was getting exhausted (causing lower density) in the center of the roll faster than near the edges, which may have had more mixing with the rest of the solution in the tank.

It's been a long time, but I believe I've heard Jobo suggest that when running prints, to avoid streaks in density, that one occasionally tip the drum up to redistribute the developer in the tank. It sounds like this is what was going on with your system, and not a water quality issue.

[paulr]

A few thoughts ...
There's a difference between deinonized water and distilled water. Not sure what it is, but a friend with an analytical chemistry background convinced me there's no imaginable reason to use deionized water for photo. distilled from the supermarket is fine.

As far as finding out water chemistry from the utility, this presumes a few things: 1) they actually know correct information; 2) the water chemistry stays the same after it leaves the utility--in other words, it doesn't pick up or lose anything in the pipes under the street or in your house; and most significantly, 3) you know all the ways the water chemistry will influence development, which is more than any photochemists seem willing to claim.

On photoflo in the developer or presoak, I've never tried this. The idea behind an alkaline presoak isn't to reduce the surface tension, but to swell the emulsion, which seems to encourage even absorption of developer . The alkali in the developer swells the emultion also, but if the initial developer flow is uneven, then the initial emulsion swelling will be uneven too.

Low quantities of developer, or developers with low concentrations of developing agents, or developers that encourage accutance effects, are all common contributors to edge density buildup. All of these are minor when compared to the design of the drum itself, but the jobo products seem to be quite good (i'm assuming you're not using an ancient one).

[bob carnie]

Above folks
Paulr idea,s of an alkaline pre-soak is one I am definately going to try, I don,t know how I missed this little jewel of info. I went back to my copy of Gordon Hutchings Book on Pyro, I bought this book when it first came out, and sure enough in the section dealing with film problems , he mentions an alkaline presoak.
I hope this helps me with the road rut problem as taking the drum off and agitating is a pain in the ass and goes against Jobo logic.thanks paulr ,one small paragraph could mean a lot in solving this problem

[Nick_3536]

Bob I don't think you've mentioned which reels you're using. If you're using the smaller 1500 tanks then you'll find others have made similar complaints. Supposedly they got around the problem by switching to the 2500 tanks and reels.

[Kirk Keyes]

paulr - there is a difference between deionized and distilled water. The goal of both deionized water and distilled water is the same - pure water, they just use different processes.

Deionized water could use a reverse osmosis system that is fed into deionizing resin beds to scrub that last few ions from the water, or for a low volume system it could just be a series of resin beds. Distilled water is just that, water that has been distilled. The still could be made of stainless steel, copper, or glass. The materials that the still is made out of will have an influence on the types of impurities in the water.

Distilled and deionized water will be functionally equivalent for most any photographic purposes, especially the ones we are talking about here. So yes, buy the one that is least expensive in your area.

Bob - certainly try the alkaline prewash. Even though paulr points out that the alkaline prewesh isn't necessarily to lower surface tension on the film, it actually will do this as well by wetting the surface of the film.

Here's something I've done - when processing PMK, you can take advantage of the split nature of this developer and use one half of it as an alkaline prewash. If you are using 1 liter of developer, place the Part B into 500 mls of water and pour that into the Jobo. This is enough to cover the film and let it get wet. After your prewash time is over (just a couple minutes are needed), don't pour that liquid out, but add another 500 mls of water with the Part A. When the two solutions mix in the tank, the developer will begin working as normal.