Jobo 1520

Discussion in 'Darkroom Equipment' started by maddermaxx, Nov 8, 2007.

  1. maddermaxx

    maddermaxx Member

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    Hey guys. I have a Jobo 1520 tank and I want to develop only 1 roll of 35mm in it, do I still fill it up to 485ml or can I use enough to just cover the roll? (about 300ml)
     
  2. john_s

    john_s Subscriber

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    Enough to cover the roll is fine (I think 250mL will do it- better check). But, if you do inversion agitation, it will effectively be more vigorous because the developer will move more and probably faster unless you're very gentle. Also, if you're using a very dilute sort of developer, or one that oxidises quickly, it might lose some power faster than usual, but ordinary developers should be fine.
     
  3. haris

    haris Guest

    I use 500ml in my Jobo 1520, regardless if I develop 1 or 2 rolls of 35mm or 120 films. I use hand agitation (inversion method), I don't use Jobo processor. I mostly use reusable developer (ID11). Never the less, when use one-shot developer, like Rodinal or Perceptol, I again use 500 ml of working solution. Maybe I do waste 250 ml stupidly :smile:

    There is another method, that is rolling tank on floor or better in Jobo gadget made for that, and Jobo tells with that method you need only volume of chemiclaals like is needed when use in Jobo processor (260 ml). But, I never tried that "rolling" method, so I don't know how it really works...

    Never had any problems with 35mm films regardless if I develop one or two at same time, and I had problems with overlaping two 120 films, but that was my fault, I didn't properly load films on reel.
     
    Last edited by a moderator: Nov 16, 2007
  4. snowblind

    snowblind Member

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    Hi guys, first post to the forum here but thought I'd reply to this since I'm considering a 1520 myself and am looking at tank capacities on the Jobo site right now.

    According to them, it takes 250ml to inversion-process 1 reel of 35mm in a 1510 tank and it takes 485ml to inversion-process 2 reels of 35mm in a 1520 tank. So, can we deduce that it takes 250ml, as with a 1510, to do 1 reel in a 1520?

    If using the same volume in the 1520 as in the 1510, then mightn't the film be completely out of the chemical altogether when the tank is inverted or does this matter for that brief period? Leads to another question too: am I right in thinking that the reels are only ever at most half covered during rotary processing since there's a hole in the centre of the tank lids used for that?

    As you might guess, I'm new(-ish) to home developing in general, not just Jobo, having only ever done it when I took a course 11 or 12 years ago. I'm looking at Jobo tanks instead of any others so that I can upgrade to a CP* processor at some stage if I want to and if people stop handing over such outrageous prices for them on the 'Bay! In fact, B&H must have spotted this trend too since I've noticed they put their price on a new CPP-2 (which they probably don't even have) up to $3500!
     
  5. jeroldharter

    jeroldharter Member

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    I am not doing 35 mm anymore so I might be a bit off. But a couple of things to consider. The volumes for Jobo tanks are usually posted for rotary processing with the tank horizontal. You must supply enough volume so that the film on the innermost part of the reel is immersed in fluid when the tank rotates. Unless you use a very dilute developer, the volume required should almost always be sufficient to process the roll of film.

    If your tank holds multiple reels, I would consider loading it with empty reels when processing a less than full load just to keep the variables to a minimum. For inversion processing you will need to fill up the tank with fluid anyway so inserting the empty reels will reduce the volume required to fill the tank.
     
  6. snowblind

    snowblind Member

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    They give figures for both inversion and rotary processing for the 1500-series tanks. The figures I gave above are what they say to use for inversion. However, I'm a bit confused now looking at the film capacities for Ilford developers. According to the info in Ilford's liquid developers fact sheet, one-shot development works out to use 60ml per 36exp.

    Taking DD-X as an example, they say to dilute it 1+4 for working strength. That would mean 300ml of liquid (60ml dev. + 240ml water) to do 1 film and 600ml to do 2. Jobo, on the other hand, say to use 250ml for 1 film and 485ml for 2. Therefore I would have to assume that 300ml will not fit in a 1510 tank and 600ml will not fit in a 1520. If that assumption is correct, then how is it supposed to work out?

    If you reduce the total volume but bear in mind that you need 60ml of developer for each roll of 36, then surely your working strength dilution changes. On the other hand, if you reduce the total volume and keep the dilution the same, you presumably are not using enough developer.

    Could it be the case that the dilution is not important as long as your film is covered with the volume of liquid stated by the tank manufacturer and that liquid contains the amount of developer stated by the chemical manufacturer?

    Thanks...
     
  7. maddermaxx

    maddermaxx Member

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    Well, through my experimenting (aha) I found out, that 300ml (used water to test) is enough liquid to cover one reel sufficiently.. so should I follow dilution requirements and change to 300ml? (was just going for 500ml)
     
  8. snowblind

    snowblind Member

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    I'm even more confused than I was to start with :-/ I've found this same subject discussed in a few other threads but none of them make it any clearer (with everyone seemingly having their own way of doing things).

    Maddermaxx, you say 300ml is enough to cover one reel "sufficiently" but is 250 also enough as Jobo state? Does it take a further 300ml (making 600 altogether) to cover a second reel in the same tank or is 500ml (or even 485 as Jobo state) enough then? More importantly in the context of my particular confusion, will the tank hold 600ml at all?

    So, question for everyone: if you need, as seems to be the case for Ilford DD-X, 60ml of developer to do one film and that developer needs to be diluted 1+4, giving 300ml of solution, then to my way of thinking, you should need 600ml to do 2 films if you are to use the correct amount of developer and keep the dilution the same. What happens if your 2-reel tank will not hold 600ml? Does that mean you can't do 2 films in it? Similarly, what happens if your tank needs more than that to cover the reels? Do these figures vary depending on the combination of developer and tank?

    Seems to me that, unless all developers require the same amount of working solution per film and all tanks hold the same capacity per film (and, as far as I can see, I don't think either of those statements is true) then, depending on the combination of developer and tank, either the amount of raw developer contained in the solution must change or else the dilution must.

    Any help in clarifying this conundrum greatly appreciated!
     
  9. MattKing

    MattKing Subscriber

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    snowblind:

    There are three measurements that are critical:

    1) the capacity of the developer, and
    2) the volume of the tank, and
    3) the dilution you are seeking to use.

    You are correct - it is recommended that at least 60ml of DDX stock be used for each roll of film. You can use more, but most likely you shouldn't use less.

    The volume of diluted developer that you can use in your tank will vary over a range. The smallest amount will be the minimum amount necessary to cover the film, while the largest amount will be the maximum amount that the tank will hold.

    You may find that your tank will hold a bit more than you think, but if you are going to measure it (use water), you should measure it with reels and film installed (as they take up space).

    If it turns out that you cannot put 600 ml of 1 + 4 diluted developer into your tank, and Ilford's figure of 60ml minimum stock developer is also correct, your only choices are:

    a) to develop just one roll at a time, or
    b) to develop two rolls at a stronger dilution than 1 + 4.

    The question then becomes what the effect will be if you use developer at the stronger dilution - say 1 + 3.5 or 1 + 3?

    If the dilution is close to 1 + 4 (say your volume is 540, and your dilution therefore is 1 + 3.5), you probably just need to use slightly shorter times, to get similar results. I don't use DD X myself, so hopefully someone here who does can chime in on that.

    You may also find that the 60ml minimum per roll quoted is very conservative, and that if your total volume is 540ml, 54ml of stock per roll would work just as well. Again, I don't use DD X myself, so hopefully someone here who does can chime in on that.

    I would tend to lean toward using the stronger dilution, rather than smaller quantities of the stock, but that is just me.

    You might also try a pm to Simon Galley here on APUG. He is very helpful, and may very well welcome the opportunity to answer your question about minimum volumes publicly. You should reference this thread in your pm.

    You might also ask a moderator to revise the thread title to "JOBO 1520, 2 rolls, and Ilford DDX". Moderators always want to help :smile: and the revised thread title might attract Simon's attention anyways.

    Matt
     
  10. Paul.

    Paul. Member

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    Snowblind,
    The Jobo 1520 tank will only hold 500ml of fluid. Thats why I use it, saves 10ml per load.
    I mix my dev, acording to the manufactures instructions as all the other chemicals. so if a dev calls for 1+4=5 I divide 500 by 5 =100 so end up with 100ml dev + 400ml water for an example.

    If I am developing 1x 35mm film I use half a tank of fluid unless I am useing multi use chemicals for example T max dev which would be made up to 1 litre of working strength chemical and I fill the tank. Have done it this way for a number of years with no problems. By the way the Jobo 1520 tank is the only one I have used that does not leak when inverting during processing.
    Hope this helpful.
    Regards Paul.
     
  11. pentaxuser

    pentaxuser Subscriber

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    With only 250ml in a 1520 tank, the dev on inversion "leaves" the film completely as it fills the top half of the tank. Presumably enough of the dev clings to the film and continues action for the second or so that the dev leaves the reel. Even if it doesn't then the film is without dev for a very short period every minute presuming the use of Ilford agitation of 4-5 inversions every minute.

    However if the dev doesn't stick to the film then in a long dev cycle of say 15mins the time without dev presumably needs a correction factor needs to be built in.

    Even if the smaller 1 reel 35 mm tank is used then inversion still deprives the bottom of the reel of dev for a time as some dev flows into the cap area.

    I think that it doesn't matter as it does cling to the film and no time correction needs to be built in but does anyone know which it is?

    pentaxuser
     
  12. snowblind

    snowblind Member

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    Thanks for the replies, all.

    MattKing,
    You mention changing the concentration and compensating with the timing. I notice that manufacturers publish time compensation charts for different temperatures and that, through the likes of the "Massive Development Chart", you can adjust timing for different combinations of developer and film but how would you go about adjusting the timing for different concentrations? You use something other than DD-X so does your developer, by happy coincidence, work out to fit your tank perfectly at the stated amount and concentration or did you have to experiment also? Thanks for that contact -- I hope he won't mind a stranger PMing him (which I probably will once I actually get underway and making mistakes with this lark). Not so sure about changing the name of the thread though -- I only mentioned DD-X since I happened to be looking at its fact sheet. Rather, I was (am) hoping to get a clear idea of how any developer might work out.

    Paul,
    You seem to take the other road -- keep the concentration constant and let the amount of dev. vary. As you said, you would use 100ml of dev. if the stated concentration was 1+4 and would use half a tank of same if only doing 1 roll. Therefore you would use 50ml of dev. for 1 roll and 100 for 2 even though (sticking with the DD-X example) the amount stated by the manufacturer might be 60ml for 1 roll and, by deduction, 120ml for 2. Do you have any problems with that approach? Do you find you also need to adjust the timing to compensate for the lower amount of dev. or do you find, as MattKing suggested, that the min. amount stated by the manufacturer is actually on the generous side?

    What worries me about both approaches is how much experimentation is required everytime one tries a new developer? Knowing my (admittedly anal) approach to experimentation, I would end up wasing 10 or 20 test rolls just trying to find the perfect timing.

    Pentaxuser,
    What you said about 250ml in a 1520 was what I expected to be the case. Have you done this and it works OK with the film being uncovered very briefly? I'm hoping so since I don't want to have to use enough chem for 2 films if I only want to process 1 (although it wouldn't be that much of a problem to just wait until there are 2 to process, I suppose).

    Maddermaxx,
    I hope I haven't hijacked your thread and that either:
    a) Your question has been answered
    b) You are gaining useful information from the rest of the discussion
    c) Possibly both ;-)
     
  13. MattKing

    MattKing Subscriber

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    snowblind:

    Developer gets used up as you develop film. It takes a certain minimum amount of developing agent to cause film to develop enough to be usable. If you don't put enough of that agent in with the film, than the developer exhausts itself (runs out of capacity) before the developing cycle is finished.

    Within a moderate range, if you have more than enough stock developer in your mix, the amount of development of the film will not be constrained by the capacity of the developer, but rather by:
    1) how long you develop the film;
    2) at what temperature you develop the film;
    3) your agitation method; and
    4) how active your diluted developer is (varies with dilution).

    Most of us here use small tanks. The majority of us use film developer one shot - we discard the diluted developer after each batch of film is developed, rather than reusing and replenishing the developer. We refer to the capacity information, because we want to make sure that the developer we discard still has some life in it, rather than risking that it may exhaust itself in the tank before it has finished its work.

    DD X seems to be strange in a way. The recommended dilution and capacity information results, in the case of many of the small tanks, in diluted working strength developer that is very close to the capacity limits specified. As far as I am aware, most other developers are only likely to encounter problems with capacity in small tanks if they are used at non-standard, higher dilutions.

    I use HC110. There are a wide variety of dilutions used for HC110 (everyone has their favorite). The Kodak recommended dilution "B" has at least twice the needed capacity in most small tanks.

    With respect to experimentation, I would suggest that you are going to have to do some of that anyways. The published guides are just that - guides. If you end up using 120 ml of stock, and water to bring the tank up to being filled, you will end up with something like a dilution of 1 + 3.3. I'd try that with your development time reduced by 10% from the published times for 1 +4, and see what result you get.

    With respect to Simon R. Galley of Ilford/Harmann, I wouldn't hesitate to PM him (referring to this thread). Your questions are good ones, and any answers he might supply would help others. My perception is that one of the biggest reasons he participates here (besides the fact that he too loves analogue photography) is because it affords him, and through him Ilford, the opportunity to assist users of Ilford products (and probably encourage others to become users of Ilford products too :smile:.

    Here is an example post, to give you an idea of how helpful he can be:

    http://www.apug.org/forums/forum37/43698-paper-start-2.html#post535898

    Matt

    P.S. Simon travels a fair bit, and sometimes therefore isn't able to respond immediately to a PM.
     
    Last edited by a moderator: Nov 22, 2007
  14. maddermaxx

    maddermaxx Member

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    250 is enough, but it just BARELY covers the film, so for precaution I'd use 300, and it's easier to mix to an even number than 250ml.

    The tank will not hold 600ml, it can hold 500ml with one reel, I'd say it might be a tight fit with 2 loaded reels, but could be done.

    I generally use D-76 non-diluted and toss it after a use, so I'm not replenishing it.. But I don't really see a problem with diluting chemicals in a 300ml solution for one roll of film, should be sufficient?
     
  15. pentaxuser

    pentaxuser Subscriber

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    In answer to your question, No I have only ever used the 1510 tank which holds 1 35mm reel. I think if you use 250 in the 2 reel tank then coventional wisdom/instructions say put in the spare reel to avoid the bottom reel moving up and down. However it begs the question that if you want the reel to be covered by the developer then if it moves up and down with the developer then what's wrong with this? I think the answer to this lies in the surge effect that the reel moving up and down might have on the dev effect but that's conjecture on my part.

    What I can confirm is that when I use the 1510 1 reel tank the dev ends up in the top bowl of the tank, held in by the red rubber cup. On righting the tank the few cc's of dev takes a second or two to swirl back down the hole to the bottom as you will see if you lift the rubber top after righting the tank. In fact if you invert 4-5 times in a 10 sec period then some dev stays up in the bowl for whole inversion time. However I have never seen any adverse effect on the development of the film at the bottom of the reel. Hence my assumption, apparently borne out by the evidence of my eyes on examining the film after fixing that enough dev clings to the bottom of the film to ensure that there isn't uneven development.

    pentaxuser
     
  16. snowblind

    snowblind Member

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    Great, thanks everyone -- answers a lot for me. Probably asking a lot of questions for someone who's only starting down this road but I like to envisage a situation where accidentals are out of the equation, results are consistent and variances are deliberate. I'll get there!

    MattKing, I'll certainly PM Mr. Galley and, hopefully, we'll see his take on volumes and dilutions here soon...
     
  17. snowblind

    snowblind Member

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    P.S. Why do I have to login 2 or 3 times whenever I try to use this site?