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Thread: Determining N-2, N-1, N, N+1... etc. development

  1. #1

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    Determining N-2, N-1, N, N+1... etc. development

    I'm very new to processing my own 4x5 TMAX100, but have been reading and learning alot. I understand what N-1, N-2, N, N+1, and N+2 mean, but I don't understand how to determine how to carry out these developments. I know that you can change your development times, or you can change the dilution of your developer and the agitation cycles. If I want to move a highlight from zone VIII down to zone VII while retaining detail in shadow at zone III I would want to use an N-1 development. But I don't understand excaclty how to do this. I'm shooting TMAX100 and processing 4x5 sheets in tanks with hangers, and using TMAX RS diluted 1:4 for normal development.

  2. #2

    Determining N-2, N-1, N, N+1... etc. development

    Brian,

    I think your best (and simplest) written resource on this would be Fred Picker's "Zone VI Workshop" which you can get for little on Ebay (even try Amazon's marketplace). The testing procedures are (I think) written in simple terms. And it is the testing that you will have to do in order to get your N-1 or N+2 or whichever.

    I can't think of a fixed advise on this, as it will depend on many factors. I always believed in my own testing, because that's the only way to ensure that processing procedures are followed to the letter every time (outside of times when one forgets a step or two). This is of course, if one does indeed believe in testing to begin with.
    Witold
    simplest solutions are usually the most difficult ...

  3. #3
    Dave Karp
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    Determining N-2, N-1, N, N+1... etc. development

    Brian,

    There is a discussion of a simple way to determine film speed and development times in Steve Simmons's Using the View Camera. Another good reference for practical Zone System testing is Graves's The Zone System for 35mm Photographers. Don't let the title fool you. There is plenty of information in that book for people who use cameras of all formats. He gives you a good system for arriving at your film speed and development times.

  4. #4

    Determining N-2, N-1, N, N+1... etc. development

    I used the Zone System by Brian Lav to do testing for myself.

    Real zone system testing requires a densitometer. There are places that will test your developed negatives for you with one of these devices. But I found the approach in this book, using visual testing, to suit me just fine.

    The basic process involves a fair amount of work. But it's interesting, and it's good practice for developing sheet film. My first film tests took the better part of a day. Subsequent ones a little less.

    I would suggest looking at threads or books that use a step wedge to limit your time invested. But if you want to try it the straight forward (long) way, just grab that book.

    One word of caution on Tmax. I found that it was extremely sensitive to changes in temperature or aggitation, and that small changes in development time could mean substantial changes in contrast. If you are very consistent and careful, that's a plus. If you are not quite that tuned in, it means Tmax may not be the best choice for starting out. I found FP4 and HP5 to be much easier to work with. That meant gettting results about like I expected. If I'd only worked with TMax I probably would have given up.

    I love TMax, and still shoot it some. But for me, it's something of a hit or miss approach. The opposite of working with zones. I've got a ton of respect for anyone who can dial this film in, and I'm going to keep working on it.

    I highly encourage you to do your own zone testing. Just figuring out your personal film speed and normal development time will take you a long ways towards getting what you expect out of your negatives. Going on to figure the N+/- times is more work, but even a partial attempt will give you lots of new information.

    This is coming from a guy with only a year of hobby level experience with this stuff. Of course real zone system testing is better than a visual inspection approach. And almost anyone else responding here will know a lot more than me about the subject. But, I thought my relative proximity to your experience level might be valuable. If densitometers and dead accurate testing takes the fun out of it, try this approach and you'll get much of the benefit without anywhere near the intense effort. You can then decide to take it further or not.

  5. #5

    Determining N-2, N-1, N, N+1... etc. development

    Picking up a book is a good idea. One not mentioned above is "Beyond the Zone System" by Phil Davis. It covers basic Zone System principles as well as sensitometry in general, and is quite quantitative in its treatment - which could be a benefit or a detriment, depending upon your perspective.

    Implementing the Zone System is really just putting numbers to the phrase, "Expose for shadows. Develop for highlights." As a first guestimate, once you find the development time which gives the right densities for an N scene, try decreasing your development time by 15% to get N-1 (or increasing by 15% for N+1). That should get you pretty close. (I think most people vary development time rather than dilution.) I did my initial testing by shooting five or six rolls with the lens focussed at infinity and a uniformally illuminated card filling the camera's field-of-view. I exposed each roll from Zone 00 (two stops below Zone I) to Zone XIII, tried a range of development times, and then contact printed the negatives to get my effective film speed and development times for N, N-1, etc.

    Depending upon how quantitative you want to be, you can check your work with a densitometer but inspection by eye works fine too, i.e., "The brightest highlight which retains detail is my Zone VII." Just figure out what development times gave the right Zone VII density for N, N-1, N-2, etc. scenes. It took me a couple days to take the data but was well worth it. The other thing to remember is that your N, N-1, etc. times depend on your choice of paper grade (or contrast filter if you print with VC paper). You're calibrating your process for a specific film-paper combination. The times you come up will almost certainly not be the same if you change materials. And you also need to keep you developer temp well-controlled. If it varies by more than about 0.5 deg F from run to run, you'll probably find the variation in highlight density pretty annoying - at least that's been my experience.

    Good luck,
    Chris

  6. #6

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    Determining N-2, N-1, N, N+1... etc. development

    If I understand your question, your not sure how to conduct the testing for say, an N-1 development. If this is your question, here's my approach. It involves building a target light source that can be used for testing. (Versus trying to light a gray or white card with lights.)

    I purchased about a 3'x5' sheet of 3/8ths inch plywood (dimensions unimportant), cut about an 8 inch hole in it, and painted one side black. Opposite the black side, I positioned an 1/8th inch thick translucent white sheet of plastic against the hole. Obviously, the dimensions of the plastic must be larger than the hole. I fashioned a frame or holder so that I could position another sheet of 1/8th inch thick ground glass about 3/4 inches behind the white plastic. I built a couple of wood light-stands to stand this device up at about camera height, with the black side facing the camera.

    During use, I place a light source (using the daylight corrected, bright incandescent light bulbs that one can find in photo stores) behind the plywood. These are the blue lights that only last for about 3 hours. I found that it was important to use daylight corrected bulbs. Personally, I use three of these at one time, with the sockets positioned at the three points of an equilaterial triangle 8 or so inches on a side. I use the 250 watt bulbs. I point the camera at the black side of the target, and place the lights behind the target.

    By varying the distance between the lights behind the glass/plastic, and by using one or all three of the lights, I can achieve a broad range of light intensities on the target. By using this light source control, together with varying the aperture and using a couple of neutral density filters, I can achieve any zone from zero or one up to zone 10 of absolutely even light on the target. Of course, I photograph the target. I use a Pentax spot meter, and I check the target before every exposure. I may have the adjust the lights behind the target a bit to get the exposure spot on.

    This is the contraption I built. To address your question, let's assume that you know your normal (N) development time. Take a photo of the above arrangement so as to achieve a Zone VII intensity of light on the film at N development. Develop and process the film. Then adjust the aperture to achieve a Zone VIII intensity of light on the film. (Open aperture one stop.) Determine the decrease in development time you need so that the density of the film for the Zone VIII exposures matches the density of the Zone VII exposure when developed at N development.

    There's nothing to it. (-:

    Ditto for bringing a Zone IX down to a Zone VII for N-2, Zone VI up to a Zone VII for an N+1, etc.

    Actually, I pivot on a Zone VIII, versus a Zone VII. So, my N-1 involves bringing a Zone IX down to a Zone VIII, etc.

    In all of the above, I DO NOT vary the shutter speed. I find that apertures are usually one stop apart, and that shutter speeds are usually NOT one stop apart. I have a shutter speed tester, and I found a half-second shutter speed on my 150mm lens that is incredibly consistent. Almost all my lenses are Symmar-S or Super Angulons from the same time period, so I use this lens at this shutter speed for all my testing. I suppose I could conduct a separate set of tests using one of the Super Angulons, but I haven't found this to be necessary.

    In all of this, I tried reflecting light off a gray or white card. But, it was really difficult to obtain a consistent light source. Nor could I vary the light enough using this method to go from a Zone 0 or 1 up to Zone X. This all seems like a lot of work, but it works very well for me.

  7. #7

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    Determining N-2, N-1, N, N+1... etc. development

    I'd suggest using The View Camera Store to do the testing for you. They use Phil Davis' testing methodology as explained in his book "Beyond the Zone System." They charge about $30 and IMHO it's well worth it to eliminate wasted film and lots of time doing the tests yourself, plus they provide more information than you'll be able to get yourself unless you have a transmission densitometer and a program to plot curves.

    When you do it yourself you get different film base plus fog readings between your film speed tests and your development time tests, which always bothered me. Plus it can be diffcult to get through the exposures needed to make the tests without the light changing at some point. If the light changes while you're making the images for the tests then you have to start all over again. Bummer, wastes a lot of time and film. It might be possible to minimize this problem by using artificial light indoors. I never tried that because of something Fred Picker said in his book, exactly what I don't recall now.
    Brian Ellis
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    a mile away and you'll have their shoes.

  8. #8
    Donald Qualls's Avatar
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    Determining N-2, N-1, N, N+1... etc. development

    If the light changes while you're making the images for the tests then you have to start all over again. Bummer, wastes a lot of time and film. It might be possible to minimize this problem by using artificial light indoors. I never tried that because of something Fred Picker said in his book, exactly what I don't recall now.



    I suspect what you're referring to is the simple fact that, because incandescent indoor light is redder, and most films have slightly lower response in red light compared to blue, most films have a different (almost always lower, sometimes much lower) effective speed under incandescent light than in daylight -- and worse, different with different kinds of incandescent, because of the change in color distribution as the color temperature (related to the filament temperature) changes. And a brownout of as little as 10 volts can make enough difference to cause a problem with film testing, if you're working in the realm of densitometers and timing your development by the second while watching the temp on a thermometer marked in tenths of a degree.
    If a contact print at arm's length is too small to see, you need a bigger camera. :D

  9. #9

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    Determining N-2, N-1, N, N+1... etc. development

    I don't know why everyone is beating around the bush so much.
    Go to the Kodak web site, professional films and download the tech bulletin for T-Max films.
    The info is there.
    Basically an increase or decrease of 10% from good basic development time will go to N+1 or N-1 as the case might be.
    As another responder has indicated, T-Max films are very sensitive to temperature and agitation. You must be consistent.
    The JOhn Sexton article on the use of T-MAx films may still be available for download from Photo Techniques Magazine. It is excellent. I don't believe it is available on the Kodak site any longer.

  10. #10

    Determining N-2, N-1, N, N+1... etc. development

    If you can find a copy of Arnold gasson's handbook of Photography it it tells how to do all the tests on parimetrics etc. It is how Graves learned. Also Minor Whites book.

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