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  1. #11

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    Quote Originally Posted by Tom1956 View Post
    As for me, I'm of the school of the "straight print". No hocus pocus in the darkroom. Get the negative right and then make a straight print--it is what it is, and move on. Otherwise, if you are going to do all that manipulation, you might as well throw the negative away afterwards, because you're never going to be able to pull that negative from the file in a couple years and duplicate the first print. Make the negative your "masterpiece" and make straight prints. But that's me.

    I'm speechless. Bruised my chin when it bounced off the floor.

  2. #12

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    All I can say is that I have a set of old filters which are labelled MGII filter set and they reflect exactly what the OP has found so even the older set of filters still had an increasing magenta look until grade 3 /3.5 after which the grades 4,4.5 and 5 look lighter and less magenta.

    It might be that my higher grade filters have faded more but as they would have been used less, this seems unlikely.

    I cannot give any reason why, unlike the colour head dual filtration, the filters don't get progressively more magenta but they don't

    pentaxuser

  3. #13

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    Quote Originally Posted by silveror0 View Post

    I'm speechless. Bruised my chin when it bounced off the floor.
    I'm a printer. 35 years on the press. It's all in the plate. Not much you can do once it's on the press--not a lot, anyway. Once you've finished the press run, you throw the plate on the scrap aluminum pile, and file the negative. Next time it comes up you pull the negative, burn a new plate and duplicate the last time you ran it. It kinda conditions you in your photographic hobby.

  4. #14

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    I'll back out of further hogging your thread MR74, as it was obviously meant for people of other techniques than mine. Still like that graded paper though--cuts out one variable.

  5. #15
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    The current Multigrade filters allow the same exposure times for grades 00 to 3.5, and then double the exposure time for grades 4 to 5. That is, I believe, the reason they are not simply yellow at the low end and magenta at the high end. Older filters like that can be used, but would give varying times for each grade. I inherited a set of Kodak Polycontrast filters like that. And I do believe the current multigrade filters are optimized for multigrade IV paper.

  6. #16

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    Quote Originally Posted by Tom1956 View Post
    I'll back out of further hogging your thread MR74, as it was obviously meant for people of other techniques than mine. Still like that graded paper though--cuts out one variable.
    Tom, no need to back out. We all have different ways of doing it. In fact the thread has little to do with technique anyway. I'm just curious as to why the colours of the various filters are different in the current version of Multigrade versus the previous version which was a fairly continuous progression from yellow to magenta.

    Perhaps I'll drop Mr. Galley a note.

  7. #17

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    Quote Originally Posted by Michael R 1974 View Post
    If I remember correctly not all that long ago Ilford Multigrade filters ranged in colour along a fairly continuous progression from yellow (#00) to a fairly dark magenta (#5). This is similar to most VC heads and Ilford still refers to yellow and magenta filtration in the current tech pub discussing contrast control with MG papers.

    However the current generation of multigrade filters are not like this. They seem to be a perhaps more sophisticated set of colours. #00 looks orange. There is then the more or less expected progression to magenta through grade 3 1/2. Then a change in colour again at grade 4 onward, which seems (to the eye) to be less "magenta" than grade 3 1/2.

    The only reference I can find in Ilford's online resources is a statement that the previous incarnation of the filters was never able to deliver as low a minimum contrast as the current version. Ilford also indicates the dyes may be less stable in the previous version although it is not entirely clear whether that is intended to mean old filters should be replaced, or if it means the newer versions actually have more stable dyes.

    Did the current version coincide with the introduction of Multigrade IV? Does it have anything to do with three-emulsion paper vs older versions?

    Comments?
    VC paper is sensitive in two bands, to yellow light for low contrast, and blue light for high contrast. So the question is really how much yellow and blue the filter passes, respectively. My own sets (I have two) are of the old type. How would you describe the colour of grade 4/5 on your new set? More yellow than grade 3.5? That would be strange. If it were somehow more blue, you'd have consider that your eyes and the paper do not have the same spectral response, so it is possible that those filters just have a narrower band pass around the blue frequency. But in all honesty, unless you look at the filter spectral transmission and compare it to the paper's spectral sensitivity, you would be guessing, like I am now.

  8. #18

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    VC paper is sensitive to blue and green, not yellow. I suspect the newest colours are optimized to somehow give the widest contrast range - but the paper is a relatively complex 3-layer emulsion with different sensitivities to blue and green (effectively a blend of different speeds).

    I will ask Ilford about it.

  9. #19

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    Quote Originally Posted by Michael R 1974 View Post
    VC paper is sensitive to blue and green, not yellow.
    Yes, you are correct. Apology. But the principle is the same. The yellow filters pass green light but not blue. The magenta filters pass blue but not green. One has to be careful with colours. We see a blend of pure red and pure green light as yellow, but we also see pure yellow light as yellow. Our visual wiring is such that we cannot distinguish between the two ways of getting the same result, although a photographic paper might be a very different beast in that sense. Which is why I said one must have the spectral response of the paper at hand and compare with the transmission of the filters to see where they overlap. How the three-layer paper differs with respect to two-layer paper would be interesting. Maybe it allows them to make the low-contrast layer even lower contrast, while a mid-layer makes it a bit more controllable with a straighter, more gradual transition between grades - I don't know. What I do know, is that it works wonderfully, and saves my @$$ when I expose or develop carelessly, which happens more often than I would like to admit .

  10. #20

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    The three layers all have the same contrast. It is the difference in sensitivities to blue and green light that allow contrast control. Have a look at Ilford's tech pub for a good explanation:

    http://www.ilfordphoto.com/Webfiles/...8932591755.pdf

    I used to make the same mistake myself (as I suspect most people do) when explaining how VC papers work. Somewhere along the way (I don't remember how) we all got the notion VC paper worked by having a green-sensitive low contrast emulsion and a blue-sensitive high contrast emulsion. In fact this is not the case.

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