Paper developer test help.

Discussion in 'B&W: Film, Paper, Chemistry' started by fidget, Mar 5, 2007.

  1. fidget

    fidget Member

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    This question is more about how one can determine that the developer is too old to use reliably, rather than a question about any specific developer.
    I'm using a 4 slot NOVA tank for my 8x10 work and am presently using Ilford WT and CT developers. I am aware that they may not have a long life in the slots, but am trying to determine if I can get away with a few print sessions in say one week. As an experiment, I used some WT dev which had been stored for a couple of weeks after its last use (in an air tight bottle at 1:9). It had turned yellow, but had not gone as dark as I have seen it (but never tried it). As a test to check the minimum dev time for my RC VC paper, I exposed a few pieces under a strong table lamp, them developed each of them for different times. Starting at 1m, all of them came out as black as I expect them to go, so I thought that the developer was still viable. My first test strip at Gd5 of a contrasty scene came out with a range of tones but no black. Far before I could get a good black, the whole strip went to muddy grey. I suspected that the developer was past it, so replaced it for fresh. A similar test strip was tried and developed with good contrast, with good blacks and clear base white areas, as I had expected.
    So,newbie question: why did the (very overexposed) max density test pieces dev to black whilst the normal (from a negative in the enlarger) test strip went grey?
    Clearly, my test did not show what condition my dev was in, what would be a fair practical test?

    Regards, Dave.....
     
  2. Photo Engineer

    Photo Engineer Subscriber

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    Dave;

    It sounds as if the developer is becoming foggy with age or losing the ability to attain a usable contrast.

    You might try developing an unexposed strip in the dark to find out what happens. If it darkens, then the developer has begun to fog paper while the developer is in contact with the paper.

    Some developers lose the ability to form dmax blacks with time. If you extend development time to get black, then fog becomes too high because contrast is too low.

    Bottom line is that there are several possible reasons.

    A good developer should last about 1/2 week in an open tray (1 liter in an 8x10 tray) with adjustments in development time to achieve the original result being possible. In a Nova processor, the time should be longer than that, especially with a cover. If adjustments in time are impossible then the developer is bad.

    This is based on years of work with Dektol 1:3 in open and covered trays. This was used as one of the most common developers, and the concentration is pretty much between the most useful concentrations of Dektol.

    PE
     
  3. Bob F.

    Bob F. Member

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    When using a new developer, I generally contact print a transmission step-wedge on MGIV-RC glossy which I always have laying around. I stick it to the Nova with the date written on it. If I suspect the developer, it takes a few minutes to expose the wedge again under the same conditions and compare the old with the new.

    I've had Ilford Warmtone dev in the Nova for about 3 weeks without noticeable deterioration before I dumped it due to exceeding the recommended processed paper surface area. It was in the Nova (with clingfilm to seal it) and the darkroom is dark when not in use (!?!) so the developer will not have had much exposure to light, and none at all to daylight (not sure if this is relevant, but thought I'd mention it in case light would cause the developer to die sooner).

    Anyway, a step-wedge is possibly the simplest check.

    Cheers, Bob.
     
  4. fidget

    fidget Member

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    Thanks for the advice.
    For a test with a test negative, would you expose at a particular grade?
    I wonder if there can be a difference in the development of the two emulsions.
     
  5. Photo Engineer

    Photo Engineer Subscriber

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    Dave;

    I've tested a variety of papers, and they all seem to react to developers pretty much the same, but almost all the ones I tested test positive for incorporated developing agents. This, I think, would tend to dampen out the effects of a developer that is going bad.

    So, I can't answer with a big enough sample to say for sure yet. From prior experience though, all coatings tend to go the same way in developer going bad, they just go that way at different rates.

    Speed, contrast and dmax go down with the age of the developer.

    PE
     
  6. pentaxuser

    pentaxuser Subscriber

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    Dave. It may depend on what standard you want but if you do several print sessions a week and repeat this most weeks, I'd say that the developer will keep virtually indefinitely on the basis that you need to replace the dev you use after X prints per session so are subjecting the dev to constant replenishment.

    What's in the slot after a few weeks is not the same as you started with.The Nova Quad has great keeping ability anyway.

    pentaxuser
     
  7. dancqu

    dancqu Member

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    A test for developer activity. I use the induction time as
    a measure. When fresh develop an exposed strip. Note the
    time for First emergence of image of some expected to be
    black area of the paper. Use same exposed strips for
    subsequent activity checks.

    Any one paper and any one working strength developer may
    have an induction period of from several seconds to perhaps
    near a minute. If you suspect a DI emulsion then develop an
    exposed strip in a few ounces of carbonated water; a tsp
    of sodium carbonate will do. Expose the strip in the same
    measured way as is done for the activity tests. Testing
    four or five papers I've not found any DI. Dan
     
  8. Photo Engineer

    Photo Engineer Subscriber

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    Dan;

    This method is not accurate as it varies with emulsion type, size, and whether developer is incorporated.

    PE
     
  9. dancqu

    dancqu Member

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    Perhaps I was not clear. The method does not vary.
    Among papers there are variances for one reason or
    another and so for developers. Dan
     
  10. Photo Engineer

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    Dan;

    I guess I misunderstood, however with DI papers (we called it ID BTW) the activity can be maintained falsely by the initial 'surge' of development created by the incorporated developer, and it drops of more rapidly thereafter than non DI papers.

    So, I find that it can give a false reading by boosting initial development. So, the DI paper will work, but then a non-DI paper would fail. By your description, one would have to test each paper in the developer and not conclude it was good for a paper unless that paper passed your test.

    Ilford MGIV tests positive for me. Kodak Polycontrast IV tested very positive. Several others tested negative. I used a drop of 10% sodium hydroxide applied in the light.

    PE