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  1. #11
    Diapositivo's Avatar
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    Quote Originally Posted by krifartida View Post
    15XX system tanks have advantages and disadvantages compared to 25XX tanks.
    the 250XX tanks uses less chemistry for smaller quantities of film per process, but get less efficient as you stack them up. the 1500 are better when loaded full or with extensions, but they do not allow for 4X5 reels...

    also - i have found that even with a flat level processor the 1500 tanks as they are smaller are more prone to uneven developing on one end of the drum (usually the bottom end), where less active developer ends up due to the design of the tank, 2500 tanks suffer less from this issue.
    (underlining is mine)

    Doesn't the 25xx series use more chemicals than the 15xx series? My 1510 requires 140ml for 1 135/36 roll, and my 1520 requires 240ml for 2 135/36 rolls.

    Regarding uneven development, could you explain better the part of the quote which I underlined? The bottom of the 15xx is almost flat, there is only a small niche which is filled by the base of the rod.
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  2. #12
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    I think he means that because the dev quantity is smaller, when the tank is tilted, the shallow end will be much shallower.

    However, I don't see min-chem requirements as a limiting factor for me - for B&W I need more dev than the minima just so that it doesn't exhaust (300-500mL/roll) and for colour, I just chuck in 500mL+ then reuse it.

    I've ordered some roller extensions and some core extensions that should let me do a few rolls at once; currently considering offering on a 3010 I've seen otherwise I'll buy a 2509N ($100) from joboman.

  3. #13

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    The Jobo 25xx are made for rotary development. The 15xx in fact for inversion and they can be critiqual in rotary use.

    For sheet film the 30xx are the best however if you have no problem with the loading system of the 2509N reel, 4x5" can be done in this way too.
    My favorite store: http://www.fotohuisrovo.nl

  4. #14

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    it seems the user form the quoted post did not insert the extension arms all the way in to their slots, causing the tank to be too high.

    but the attached diagram lives no room for error, if only poeple bothered to read the effing manual before they discovered stuff does not work...

    even when 1500 tanks are filled beyond MAX capacity in rotation use, the films in any tank longer then 1520 will get more density on one end of the tank.
    IE - when loading 5 35mm in 1520+1530 using lift, the films towards the base of the tank (away from the lift) with get less developer agitation resulting in lower density. it is not a consitent thing, but i have seen it range from non issue 1/3 stop to more then -1 stop compared to same type of film in top of tank (closer to lift). this ofcourse refers to BW only. i have not seen this in C-41 or E-6.
    the bigger the tank, the greater the density gap between top and bottom. i will admit the biggest 2500 tank i used for film is multi tank 8 (2840) with 8X35mm (and the same with 2X2509 and 18 sheets of 4X5 which i did on a regualr basis for a long time) and i saw no noticeable density change from top to bottom, where as i went up to 10 rolls in 1510+3X1530, and there you can really see the films on the bottom end got less of everything. i tested this on other machines as well with similar, but as i said, not exact consistent results.

    who ever runs a commercial lab process (as i did for a while) runs in to these issues. the simple way around it is to make smaller batches.

    another thing - the chemical usage difference between 1500 and 2500 is pretty negligible unless you really do a million rolls a day so i take that comment back as irrelevant. however there is about a 30-40% difference between multitank 5 for sheet film and 3010 tanks. (560ml for max 12 plates 55ml per plate - VS 310ml for 10 plates 31ml per plate.)

  5. #15
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    Quote Originally Posted by krifartida View Post
    even when 1500 tanks are filled beyond MAX capacity in rotation use, the films in any tank longer then 1520 will get more density on one end of the tank.
    IE - when loading 5 35mm in 1520+1530 using lift, the films towards the base of the tank (away from the lift) with get less developer agitation resulting in lower density. it is not a consitent thing, but i have seen it range from non issue 1/3 stop to more then -1 stop compared to same type of film in top of tank (closer to lift). this ofcourse refers to BW only. i have not seen this in C-41 or E-6.
    krifartida, this frankly leaves me a bit puzzled.

    If the tank is perfectly horizontal, I don't see through which phenomenon the lower reels would get less agitation than the upper ones. If we except the time the developer takes to invade the tank, and to leave it, for the rest of the process the films should receive identical treatment. This difference should be constant between processes.

    Are you sure you properly levelled the tank? I found out that putting the level anywhere on the CPP-2 does not level the tank at all. Also, the lift is a strange animal and the tank does not sit perfectly horizontal on the upper basin, I clearly see that my lift tends to "bounce back", if I want it to touch the upper (red) basin (and be levelled supposing the red basin is levelled) I have to press it with my finger. If you level the Jobo, the tank will end up working slightly "bottom up". I have re-levelled my Jobo and now the machine is not horizontal, but the tank is This levelling work is the more important, the longer the tank is.
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  6. #16

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    the diameter of the tank, coupled with the shape of the funnel and i guess other design elements cause the liquid inside the tank to not travel to all areas of the tank equally. the i see that it is not consistent has to do with the fact that as you described even in a perfectly level machine or perfectly level tank the whole thing flexes under pressure. depending on the amount of chems, amount of films and even temperature, i think would affect the over all results and exasperate or reduce the density difference.

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