split filter printing

Discussion in 'Enlarging' started by hotami, Apr 1, 2006.

  1. hotami

    hotami Member

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    Hey guys, i've been experimenting with split filter printing but i need some advice. I understand the basic principles, use 2 different filters at least 2.5 grades apart, use one for part of the time and the other for the rest of the time. My question is how do you determine how much time you need for each filter. I've read that you expose with high contrast filter 1/3 of the time, and low contrast filter 2/3 of the time. Is there a better explanation of how to determine the allotted times? My professor demoed it but i was kind of zoned out.
    Thanks
    andrew
     
  2. david b

    david b Member

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    I've always used the 0 filter and the 5 filter.

    I start by doing a test strip using the 0 filter, on a full sheet of paper.

    After deciding the time using the 0 filter, I expose an entire sheet using the 0 filter.

    BEFORE removing the paper, I put the 5 filter in and do a test strip.

    This results in the time for both the 0 and the 5. I've found that the 5 filter is usually 50% of the 0 time.
     
  3. roy

    roy Member

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    I would go along with that David. Unless you are repeating prints, in my experience each print will require its own assessment using test strips for at least one very good reason - your own interpretation of how you want the final print to appear.
     
  4. leeturner

    leeturner Subscriber

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    I've also been using grade 5 and 0. One thing that I learnt from the forums at APUG is correctly exposing the second grade (e.g. grade 5) test strip. When I exposed the grade 5 test strip on top of the grade 0 I was struggling to see big differences between the times. It was pointed out that I should be covering the paper in increments instead of uncovering the paper in increments. Voila! noticeable variations in the test strip.
    The major advantage of using split grade for me is being able to burn in at a specific grade.
     
  5. Dan Henderson

    Dan Henderson Member

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    I was taught split filter printing with blue and green filters. We started with a test strip that included part of the film rebate with the blue filter to determine maximum black. Then after exposing another sheet of paper for the maximum black time with the blue filter, another test strip with the green filter to determine the time for proper highlight values. I used that method successfully for some time, until another instructor taught the right use of variable contrast filters: expose for the highlights, and then adjust the shadows using higher or lower value filters. I believe my prints look just as good with proper variable contrast filters as they did with split filtering, and the exposure process is simpler to determine and carry out. I haven't used split filter printing since, except while burning in very high or low value areas of a print, then I use 0 and 5 filters.
     
  6. Maine-iac

    Maine-iac Member

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    Although I use a colorhead for my split filter printing, the same principles apply to the use of actual contrast filters.

    My method is to find a basic starting time/filtration package for each brand of paper used.

    So, for example, I want to find the split filter times for Bergger. I begin by dialing in full yellow on my colorhead (0 or 00 filter) and making a series of test strips (3 second increments) on an 8X10 sheet of paper at the lens aperture I want to use (in my case f/11). Then I do the same on a second sheet of paper using full magenta (#5 filter). I develop both sheets. On the low contrast sheet, I find the strip where brightest highlight shows just a hint of texture/detail. Let's say it's 6 seconds. On the high contrast sheet, I look for the darkest shadow where I want to see texture and detail and find the strip that gives me what I want--say, 8 seconds.

    On my next test sheet, I expose the whole sheet at 6 seconds full yellow and 8 seconds full magenta (or corresponding filters). Then I look carefully at it to judge how close I am. Maybe it's close enough that I'll let it dry and check it afterward for drydown effect before tweaking the times. Maybe it needs another second of magenta to give it the snap I want or another second of yellow to soften it a bit, and I'll make the change immediately.

    But after drying the tests, I'll be able to tell what my basic start time for that paper is. Any subsequent negatives printed on that paper at that magnification, will use that basic time (e.g., 6 seconds yellow and 8 seconds magenta) for the first work print. Usually, it will be very close on the first try.

    If I want to print larger (e.g. 11X14) on the same kind of paper, I simply scale up the times accordingly keeping the ratio between yellow and magenta the same (e.g., 9 seconds Y and 12 seconds M) as a starting point.

    The key is, each paper is different, so you have to test for each paper you use. But once established for each paper, your basic time/filtration will get you very close on your first try.

    Larry
     
  7. Maine-iac

    Maine-iac Member

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    While I generally agree with your theory, in practice, I've found that split filtering improves the local contrast (the micro-contrast within a particular tone) of the print. I began using split filter printing when I discovered that my prints with this method "sing" more than they used to. It's a subtle, but real difference. Particularly in the middle gray tones, there is just a little extra luminosity that single-filter printing didn't produce to the same degree.

    Larry
     
  8. jeroldharter

    jeroldharter Member

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    I have been split contrast printing for the last few months. Although I am new to large fromat B&W I have been interested in darkroom work and photography for over 20 years. I just spent my first day using the RH Designs StopClock Professional timer and I am a convert. There is a bit of a learning curve (I am still on it) but once you get going it keeps getting better. F-stop printing is so much more reasonable and consistent with the negative exposure side of the equation. Also, using it forces you to understand the process and materials better. I already am thinking in f-stops instead of seconds and making better prints. Split contrast burning also makes more sense to me. I highly recommend it to anyone with the money for it. (Lets hope for a recession in Great Britain.) I bought mine through their website and received it very promptly.

    Not trying to be a salesman but it really is a great piece of gear. I saw on APUG that DigitalTruth is selling a similar but cheaper/fewer-featured f-stop timer also.
     
  9. BWGirl

    BWGirl Member

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    I cannot agree with you more, Doc! :wink: I also use this timer and it has changed my printing life for the better.

    I took a printing workshop with Les McLean last spring, and I really find that split filter (#0 & #5) printing gives tons of control. There was something Les said that no one has mentioned so far... 'a little bit of #0 goes a long way' or something to that effect. That's why I don't really think you can say "25% of the total time or 50% of the total time is one filter or another. I really think it's totally dependent on the negative. I really think you need to make the test strips for each negative to see.... if you try to put it 'in a box', it just limits your scope of the situation... IMVHO. :D
     
  10. roy

    roy Member

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    That was the rationale behind my posting. It works whatever timing system you use for darkroom exposure.
     
  11. argus

    argus Member

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    Discovering split-grade printing last year helped me a lot in improving my skills, but not so long ago, I starded f-stop printing... it's logical and saves me a lot of paper!

    I as myself why I did not start f-stop printing before! Now find myself a decent f-stop clock. I am now dialing in the times manually on my old timers.

    G
     
  12. Les McLean

    Les McLean Subscriber

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  13. FrankB

    FrankB Member

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    Another 0 and 5 practitioner here, following Les's method in my own thumb-fingered way! As Les says, the G0 exposure places the palest detailed highlight tone where you want it, the G5 exposure places the deepest detailed shadow tone where you want it. These may be just off paper-base and DMAX, or you may choose to place them elsewhere.

    I used to guestimate a grade, do a test strip for time and then fumble towards the correct settings by trial and error. Sometimes it would come quickly and other times it prove prove annoyingly elusive.

    Now, two test strips and that's my base exposure pretty much in the bag with just dodging and burning to worry about ("just" he says; Hah! :rolleyes: ).

    At first glance it seems like a slower and more complex way of working, but I have to say that the reverse usually proves to be the case.

    All the best with your endeavours!

    Frank