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Thread: Reciprocity issues

  1. #1

    Reciprocity issues

    I think I understand the cause of the issue I am having. I was shooting in a forest under overcast conditions and I placed my zone III in the shadows where I wanted to see some detail (right under the central root towards the top of the rock). My exposure worked out to be 30 seconds with FP4+ that I rate at 80, due to reciprocity failure my adjusted exposure was 156 seconds so I did a 2 1/2 minute exposure. Zone III turned out about perfect but the lighter components within the image seem to be way overexposed. From what I understand that is because the brighter areas are less affected by reciprocity failure than the darker areas. I didn't realize how severe this problem was till I took a look at the negative. In the future I can try and cut my development time down but Steve Simmons thinks that FP4+ expands well but doesn't contract well. I'm developing with D76 1:1 in a Jobo 3010 on a Beseler motor base with a 5 minute presoak so my developing time is only 5 minutes. My question is, should I move to HP5+ for a couple stops more speed since that will give me more breathing room before I have to deal with this degree of reciprocity failure? I'd love to try Acros but it seems to be REALLY expensive since it only comes in quickloads.

    The images are shown below:
    The first is an unmanipulated scan from my 4990 with Silverfast Ai
    The second was 2 stops less exposure at the scanning step with Silverfast Ai
    The third image was made from the second scan with a simple level and more complicated curves adjustment in CS3

    Any thoughts would be appreciated.

    Scott Kathe

  2. #2

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    Re: Reciprocity issues

    I've had the same issue with fp4 and it's the only problem i have with that film. I'd rate it at 125 next time for a long exposure such as this. Nice shot by the way.

  3. #3
    Vaughn's Avatar
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    Re: Reciprocity issues

    I think you will find that FP4+ will "contract" fine to account for the increase exposure to deal with RF.

    But the proof will be in the printing rather than in the scan. What will be your media for making a print? Also your print size comes into play -- losing a little detail in very small shadow areas is relatively unimportant in regards to the whole image -- but greatly enlarged, those shadow areas become larger, thus more important.

    Vaughn

  4. #4

    Re: Reciprocity issues

    If the rumor that the film freestyle used to sell as ultrafine was Ilford fp4 is true, then I can tell you that fp4 contracts very well and is capable of good development times even when reciprocity compensation is used, it is all I used for my 12x20.

    SInce I use the BTZS I am unable to give you better times, but I would recommend to you that you skip the pre soak, it increases contrast. That you dilute your developer 1+2 and that you increase the rating to 125 as was posted above. You should be able to get a good neg with fp4.

  5. #5
    Resident Heretic Bruce Watson's Avatar
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    Re: Reciprocity issues

    Quote Originally Posted by Scott Kathe View Post
    Zone III turned out about perfect but the lighter components within the image seem to be way overexposed. From what I understand that is because the brighter areas are less affected by reciprocity failure than the darker areas.
    It often happens that the lighter parts of the scene keep that part of the film above the reciprocity failure limit completely. So some of the film is in reciprocity failure mode, and some is not. This of course drives your exposures crazy. Yet, you still have to expose for the shadows.

    The develop for the highlights part is more interesting here. You could try decreasing agitation to semi-stand or even stand development -- let the developer exhaust in the highlights which will keep them from "over developing" as it were. Another approach is to try a two-bath developer like divided D76 -- accomplishes the same thing more or less (developer exhaustion in the highlights).

    But for my work I decided to go with a more modern film with much better reciprocity characteristics. Something along the lines of Tmax, Acros, or Delta. BTW, Badger Graphic Sales has Acros in quickloads and in loose sheets.

    Bruce Watson

  6. #6

    Re: Reciprocity issues

    Quote Originally Posted by Vaughn View Post
    I think you will find that FP4+ will "contract" fine to account for the increase exposure to deal with RF.

    But the proof will be in the printing rather than in the scan. What will be your media for making a print? Also your print size comes into play -- losing a little detail in very small shadow areas is relatively unimportant in regards to the whole image -- but greatly enlarged, those shadow areas become larger, thus more important.

    Vaughn
    For now I'm doing inkjet prints on a cheap Epson R220 running with MIS Eboni black and I print in black only mode so my maximum print size now is 8x10. I think I may end up with an R2400 or a B9180 (or HPs less expensive but similar printer) this summer. My maximum print size would be 11x14 and maybe a 16x20 if I had someone like WCI do a better scan.

    Scott

  7. #7

    Re: Reciprocity issues

    Quote Originally Posted by Jorge Gasteazoro View Post
    If the rumor that the film freestyle used to sell as ultrafine was Ilford fp4 is true, then I can tell you that fp4 contracts very well and is capable of good development times even when reciprocity compensation is used, it is all I used for my 12x20.

    SInce I use the BTZS I am unable to give you better times, but I would recommend to you that you skip the pre soak, it increases contrast. That you dilute your developer 1+2 and that you increase the rating to 125 as was posted above. You should be able to get a good neg with fp4.
    I've definitely thought about skipping the presoak but the darn presoak comes out almost black and the thought of that in with my developer bothers me. I used to develop in trays without a presoak and never saw the 'black'-I wonder if the high pH of the developer stops the color from showing up. People seem to get close to the Ilford published times without the presoak. In general I am very happy with most of my FP4+ negatives.

    Scott

  8. #8

    Re: Reciprocity issues

    Quote Originally Posted by Bruce Watson View Post
    But for my work I decided to go with a more modern film with much better reciprocity characteristics. Something along the lines of Tmax, Acros, or Delta. BTW, Badger Graphic Sales has Acros in quickloads and in loose sheets.
    I've been under the impression that Tmax and Delta are pretty finicky with respect to processing so I'm trying to steer clear of them. I'd love to try Acros but Badger lists the loose sheets as out of stock. I have a friend in Japan and work with another Japanese person and I may see if they can get the film for me but I'm really concerned about the film being opened or x-rayed when it leaves Japan and/or arrives here in the states.

    Scott

  9. #9

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    Re: Reciprocity issues

    I have found delta to be very easy to process. I have a hard time messing up development with delta.

    If you are scanning, and you are able to "expose 2 stops less" with Silverfast, why bother worry about exact exposure? It seems like the results would be about the same as N-2 development when your output is an inkjet.

    Just out of curiosity, how does pre-soaking increase contrast?

  10. #10

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    Re: Reciprocity issues

    Increasing exposure time past 8 seconds due to reciprocity failure calls for a decrease in development time for conventional films such as FP4 unless you want the increase in contrast that results from the increased exposure. According to the table I use that was provided by John Sexton in one of his workshops, a metered time of 30 seconds and an exposure time of 136 seconds with conventional films (i.e. non-TMax type) will give you the equivalent of approximately N+2 development if you develop for your normal time. In effect you've bumped your highlights up by roughly two stops, which is why you got the overly bright highlights that you got.

    So instead of developing at your normal time and getting the effect of N+2 development in that situation, develop for approximately your N-2 time or thereabouts. Obviously a little personal testing would help if you frequently encounter situations where reciprocity failure affects your exposure but this should give you a pretty good starting point. This only applies to non-TMax type films because as Bruce noted, those films are less affected by reciprocity failure than conventional films.
    Brian Ellis
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    a mile away and you'll have their shoes.

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