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#1
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split filter paper developing
I used to have an article from Zone VI Studios about split filter paper developing. I moved, and can't find the directions. Anybody have some help on this please? -- foto phred ------------------------------------------------------------------------ View this thread: http://www.photographytalk.net/viewtopic-171060.html Send from http://www.photographytalk.net |
#2
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split filter paper developing
"foto phred" wrote in message ... I used to have an article from Zone VI Studios about split filter paper developing. I moved, and can't find the directions. Anybody have some help on this please? -- foto phred ------------------------------------------------------------------------ View this thread: http://www.photographytalk.net/viewtopic-171060.html Send from http://www.photographytalk.net I think you are asking about a method that is supposed to change the gray scale of the paper. It doesn't work and is based on a misunderstanding of how variable contrast papers work. One can get intermediate grades of contrast by printing part of the time through a high contrast filter and a low contrast filter but the results will be no diffent than gotten with a single filter of the correct grade. There will be no change in the relative contrast of shadow and highlight areas. The contrast of vc paper is determined by the relative exposure of a high and low contrast element in the emulsion. The curve shape is fixed and can not be modified by exposure. However, it is possible to dodge and burn using VC filters to obtain different contrast values in different parts of the image. This is done by masking off the areas of the image that are to be printed with different contrast values and printing them in separately using the appropriate filter. This is a lot of work but can get very much improved prints where the range of density in the negative is beyond the capacity of the paper. It gives an additional control over normal dodging and burning, which contolls only exposure. -- --- Richard Knoppow Los Angeles, CA, USA |
#3
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split filter paper developing
Richard, I hate to disagree with someone as knowledgeable as you, but
I've been doing split filter printing with VC papers for many years and wouldn't go back to single filter printing for anything. My practice is to give one exposure at full magenta (I use a colorhead) and one at full yellow. The number of seconds for each varies with the paper and degree of enlargement. The differences in this and in single exposure printing with a mixture of magenta and yellow or a single contrast filter is subtle but very real. There is a visible and distinct improvement in local contrast. The tones take on a glow and "sing" more than they do with a single exposure. It also makes printing easier--less burning and dodging, though I do both when necessary, sometimes with both colors if I'm increasing or decreasing density, or sometimes only with one or the other if I'm raising or lowering contrast in a particular area of the print. Larry Richard Knoppow wrote: "foto phred" wrote in message ... I used to have an article from Zone VI Studios about split filter paper developing. I moved, and can't find the directions. Anybody have some help on this please? -- foto phred ------------------------------------------------------------------------ View this thread: http://www.photographytalk.net/viewtopic-171060.html Send from http://www.photographytalk.net I think you are asking about a method that is supposed to change the gray scale of the paper. It doesn't work and is based on a misunderstanding of how variable contrast papers work. One can get intermediate grades of contrast by printing part of the time through a high contrast filter and a low contrast filter but the results will be no diffent than gotten with a single filter of the correct grade. There will be no change in the relative contrast of shadow and highlight areas. The contrast of vc paper is determined by the relative exposure of a high and low contrast element in the emulsion. The curve shape is fixed and can not be modified by exposure. However, it is possible to dodge and burn using VC filters to obtain different contrast values in different parts of the image. This is done by masking off the areas of the image that are to be printed with different contrast values and printing them in separately using the appropriate filter. This is a lot of work but can get very much improved prints where the range of density in the negative is beyond the capacity of the paper. It gives an additional control over normal dodging and burning, which contolls only exposure. |
#4
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split filter paper developing
They are definitely different! You do wind up with different response
curve - by reason of the different exposure times at the two grades, if nothing else. I use split printing when I want the tonality of a lower grade, but the blacks just aren't there. Often a problem with underexposed negatives. First, do a test strip on the shadows with a grade 5. Pick the interval just before the deep shadows become true black. (Grade 5 Exposure) Then expose a strip on grade 5 at the Grade 5 Exposure. Then switch to a grade 0 or 00 filter and (on the same strip) do a test as per normal. Pick the exposure that which shows the detail in the highlights (Grade 0 Exposure). Then do you test print - first with the grade 5 filer at the Grade 5 Exposure, then with grade 0 (or 00) at the Grade 0 Exposure. Hold the filters under the enlarger lens (instead of placing them in the drawer) to avoid any enlarger movement. You may have to then tweak the Grade 5 Exposure and Grade 0 Exposure. If the shadows are blocked up, back off a little on the Grade 5 Exposure. If the highlights aren't there quite, increase the Grade 0 Exposure. The Grade 0 exposure time might be quite short. Split printing doesn't work for everything, but is very useful for many underexposed negatives with weak blacks - especially twilight and night shots. Other alternatives to split printing include dodging and burning (of course); simply printing on a high grade (which gives you separation of close tones & perhaps burning on a low grade to give tonality to areas of the print) and flashing to give detail to highlights. Cheers Gareth |
#5
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split filter paper developing
Richard is absolutely right. I have verified it emirically. Split-grade
printing is a myth. The crystals don't care whether in what order they are exposed. The contrast obtainable by simultaneous or successive exposure is exactly the same. LR Kalajainen wrote: Richard, I hate to disagree with someone as knowledgeable as you, but I've been doing split filter printing with VC papers for many years and wouldn't go back to single filter printing for anything. My practice is to give one exposure at full magenta (I use a colorhead) and one at full yellow. The number of seconds for each varies with the paper and degree of enlargement. You can get exactly the same effect by ONE exposure. The differences in this and in single exposure printing with a mixture of magenta and yellow or a single contrast filter is subtle but very real. No, it's not. You may be seeing some difference in contrast because you have not matched the two exposures properly. There is a visible and distinct improvement in local contrast. The tones take on a glow and "sing" more than they do with a single exposure. It also makes printing easier--less burning and dodging, though I do both when necessary, sometimes with both colors if I'm increasing or decreasing density, or sometimes only with one or the other if I'm raising or lowering contrast in a particular area of the print. Larry Richard Knoppow wrote: "foto phred" wrote in message ... I used to have an article from Zone VI Studios about split filter paper developing. I moved, and can't find the directions. Anybody have some help on this please? -- foto phred ------------------------------------------------------------------------ View this thread: http://www.photographytalk.net/viewtopic-171060.html Send from http://www.photographytalk.net I think you are asking about a method that is supposed to change the gray scale of the paper. It doesn't work and is based on a misunderstanding of how variable contrast papers work. One can get intermediate grades of contrast by printing part of the time through a high contrast filter and a low contrast filter but the results will be no diffent than gotten with a single filter of the correct grade. There will be no change in the relative contrast of shadow and highlight areas. The contrast of vc paper is determined by the relative exposure of a high and low contrast element in the emulsion. The curve shape is fixed and can not be modified by exposure. However, it is possible to dodge and burn using VC filters to obtain different contrast values in different parts of the image. This is done by masking off the areas of the image that are to be printed with different contrast values and printing them in separately using the appropriate filter. This is a lot of work but can get very much improved prints where the range of density in the negative is beyond the capacity of the paper. It gives an additional control over normal dodging and burning, which contolls only exposure. |
#6
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split filter paper developing
I follow the same testing pattern as you suggest, but dialing in the
filtration on my colorhead. By the way, despite turning the dials between exposures, I've never experienced any movement of the head that messes up the second exposure. I think it's not a problem using the filter drawer, so long as you let the enlarger come back to rest after inserting it. I use this method exclusively for all negs. Larry Gareth wrote: They are definitely different! You do wind up with different response curve - by reason of the different exposure times at the two grades, if nothing else. I use split printing when I want the tonality of a lower grade, but the blacks just aren't there. Often a problem with underexposed negatives. First, do a test strip on the shadows with a grade 5. Pick the interval just before the deep shadows become true black. (Grade 5 Exposure) Then expose a strip on grade 5 at the Grade 5 Exposure. Then switch to a grade 0 or 00 filter and (on the same strip) do a test as per normal. Pick the exposure that which shows the detail in the highlights (Grade 0 Exposure). Then do you test print - first with the grade 5 filer at the Grade 5 Exposure, then with grade 0 (or 00) at the Grade 0 Exposure. Hold the filters under the enlarger lens (instead of placing them in the drawer) to avoid any enlarger movement. You may have to then tweak the Grade 5 Exposure and Grade 0 Exposure. If the shadows are blocked up, back off a little on the Grade 5 Exposure. If the highlights aren't there quite, increase the Grade 0 Exposure. The Grade 0 exposure time might be quite short. Split printing doesn't work for everything, but is very useful for many underexposed negatives with weak blacks - especially twilight and night shots. Other alternatives to split printing include dodging and burning (of course); simply printing on a high grade (which gives you separation of close tones & perhaps burning on a low grade to give tonality to areas of the print) and flashing to give detail to highlights. Cheers Gareth |
#7
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split filter paper developing
"Richard Knoppow" wrote
"foto phred" split filter paper [exposure] ... help ... please? One can get intermediate grades of contrast by printing part of the time through a high contrast filter and a low contrast filter but the results will be no different than gotten with a single filter of the correct grade. I will second this. Identical results are produced by split filtering and filtering with one filter. However - split filtering does allow intermediate contrast grades. The contrast grades with VC printing filters are not evenly spaced. The spacing gets worse when using different filter/paper combinations such as Kodak filters with Ilford papers. When it comes to dodging and burning split filtering with two gel filters or a manual color head is a real PITA. Split filtering is easier with computerized multi-lamp heads that vary the timing of the two tubes/lamps and with automatic filterwheel systems such as the Heiland Split Grade. A continuously variable color or VC head should obviate any advantage to split filtering as all intermediate contrasts are available. The problem is translating the traditional two test strip high-contrast/low contrast results into filterwheel settings. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. To reply, remove spaces: n o lindan at ix . netcom . com Fstop timer - http://www.nolindan.com/da/fstop/index.htm |
#8
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split filter paper developing
Yes, it's an interesting issue.
I use filters. With the type of negatives I use split printing for (i.e badly exposed ones), I use long grade 5 exposures and very short grade 0/00 exposures. I suppose that, in strict theory, this translates into somewhere between grade 4.5 and 5 (essentially, magenta with a splash of yellow). But the splash of yellow is a very precise thing. Theoretically, that could be reproduced with a single exposure with a colour head - but you'd have to test to get the yellow right. So, you'd probably start with a magenta equivalent to a grade 5 - get the exposure right for the blacks - one test strip. Then you would need to start adding yellow until the highlights / mid tones were ok (one test strip at least, perhaps more) Meaning, I suspect you'd be in the same place - but with at least 2 tests, perhaps more. Any thoughts? Regards Gareth |
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