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Thread: VC & Color Head - What Filters to Start?

  1. #1
    Hack Pawlowski6132's Avatar
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    VC & Color Head - What Filters to Start?

    Something's not right in my darkroom. I have negatives (8x10 TXP) that I'm trying to contact print that look pretty damn good.

    My maximum black test tells me to expose for six bursts of three seconds each. I'm using Ilford MG VC FB Warmtone paper. Then, to expose the paper I set my Omega Dichroic filtration to 41Y/32M. This, according to Ilford is the #2 MULTIGRADE filter equivalent: Prints suck. they look gray and w/o expexcted contrast. They look much better when I print at the equivalent #3 MULTIGRADE filter equivalent of 23Y/56M.

    What gives? I want to standardize my negative exposure to print straight on #2 and I feel that I'm doing that but...

    I think somethings amiss but, I can't put my finger on it. I'm going to try to find my Omega instructions and see what they recommend for filter settings.

    Just thought I ask here too.

    thanx in advance,

    Joe

  2. #2
    Peter
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    Re: VC & Color Head - What Filters to Start?

    I've always printed with one color filtration for contrast control, either yellow or magenta. I see that Ilford has filtration suggestions for a 2 color method, but if that's not working for you, try using just one color. Here is a chart by Ilford for either method.

    http://www.ilfordphoto.com/Webfiles/...0201152306.pdf

    Peter

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    Vlad Soare's Avatar
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    Re: VC & Color Head - What Filters to Start?

    There's no point in using yellow and magenta together. Look at it this way: maximum yellow is the softest grade achievable with your printing head and paper. Then, by dialing in less and less yellow you get an increasingly higher contrast, until you get to zero (no filter). From this point onwards, to further increase contrast you dial in magenta. Maximum magenta is the highest grade achievable with this head and paper. Look at it as a continuous scale ranging from maximum yellow to maximum magenta, with zero in the middle.

    Despite common belief, printing on VC paper with no filters at all won't give you a contrast similar to a normal grade paper. That's because incandescent bulbs give yellow light. You need to dial in a little magenta to compensate for the color temperature of the bulb. With my head (Chromega Dichroic II) I find that negatives that print well on normal grade paper need about 25% magenta on variable contrast paper to print the same.

    The only reason for using several filters at the same time would be to calibrate your system so that you can switch from one grade to the next without changing the exposure time. In that case you would also need to use the cyan filter. Personally, I find this procedure awkward and wouldn't bother using it.

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    Re: VC & Color Head - What Filters to Start?

    Quote Originally Posted by Pawlowski6132 View Post
    My maximum black test tells me to expose for six bursts of three seconds each.
    Why are you exposing for "six bursts of three seconds each" each rather than one exposure of 18 seconds (or whatever is the equivalent of your 6x3, allowing for ramp up / decay properties of your enlarger lamp)?

  5. #5
    Hack Pawlowski6132's Avatar
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    Re: VC & Color Head - What Filters to Start?

    Thanx guys. Yup, that makes sense. I too have the Chromega Dichroic II and the manual presents the No. 2 Plycontrast Filter equivalent as being 3Y/22M. Not sure why they include any yellow at all but, that seems to align more with your advice than the Ilford documentation. So, that's definitely the route I'll take.

    But, I'm more than curious now to understand why such a reputable institution such as Ilford would recommend such misleading information???

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    Re: VC & Color Head - What Filters to Start?

    VC has two emulsions, one green sensitive [ low contrast] , one blue [ high contrast]
    I use Roscoe acetate filters, green and "minus green" which is magenta, and once in a very great while, blue. I have no interest in what an equivalent real filter would be, account papers vary, and A paper varies with age, in my experience starting out high contrast and losing contrast as it ages. And I use a cold light, probably overly blue. Your "misleading" comment is too strong- YMMV when you deviate from standard filters [and they include red, to which paper is not sensitive, to kill some light and keep exposure in a narrower range when changing filters]. So, armed with the green-vs-blue basics, and recalling how RGB is related to YCM, mess about with the dichroic settings until you get what you want to see, and where to start- It won't take that much time and paper to find a starting point for your next negative . Afterall, even if you could walk right up to the enlarger and dial in "#2" the chances of that being better than close-with-an-indication-of -which-way-to-go is nil- that's why variable is so valuable.

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    hacker extraordinaire
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    Re: VC & Color Head - What Filters to Start?

    I want to standardize my negative exposure to print straight on #2
    Why?
    Science is what we understand well enough to explain to a computer. Art is everything else we do.
    --A=B by Petkovšek et. al.

  8. #8
    bob carnie's Avatar
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    Re: VC & Color Head - What Filters to Start?

    Non stained normal exposed normal processed negs depending on base fog of film will be starting any where between 10mag -30 magenta
    Stained normal negs will start somewhere between 25magenta -50 magenta.

    I do not use yellow and magenta at the same time.

    I do not like doing 3 second bursts. I know some who do and I think it is silly. logic being that one can dodge , burn more accurately.
    I find that counting every time you press the timer and getting your seconds correct in your mind is the only way to dodge and burn.

    I use a dichroic for split printing and will start with 10 magenta, then a full blast of 200magenta at established base times that give a soft and light print.

    then you can burn in with your 10magenta , or your 200 magenta and 200 yellow or all three.

    Very rarely will I find a negative , which does not have a starting point between 10-50 magenta.

    Yellow is rarely used and higher than 50 magenta as a starting point.

    sound confusing,, actually just go in and use one filter to start and see how it works and soon you will see how easy it is.

  9. #9
    Hack Pawlowski6132's Avatar
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    Re: VC & Color Head - What Filters to Start?

    Thanx everyone. I just had some good results keeping yellow off and playing with magenta. But, when doing a maximum black test for a contact print, what are your settings? How do you establish an exposure duration?

  10. #10
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    Re: VC & Color Head - What Filters to Start?

    There's too many variables to expect good negatives to look perfect without filtration on VC paper. That why it's variable. The goal would be that you would not have to use excessive filtration to get the print you want (such as grade 0 or >grade 4). My personal goal is to be able to print any negative between grade 1.5 and 3 and have it look great. Anything outside of that range is caused by over/under exposure or developement errors.

    One thing unmentioned was the paper developer. Mix up a fresh batch. I've seen that make a huge difference.

    I don't do max black tests. I just print it. If it doesn't look black enough, it either needs more time or more magenta. If your negative can print in the 1.5-3.5 contrast grade range, either proper time and/or contrast can make it so you have deep blacks and clean whites very easily. Contrast is a subjective selection. Time can be determined with a test strip.

    I don't do bursts of light either. I would do 18 seconds rather than 6 3 second bursts. 18 seconds is more accurate as the bulb is a continuous brightness during this exposure rather than glowing out 6 times.

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