Contrast filter colors

Discussion in 'Enlarging' started by reinis, Apr 13, 2005.

  1. reinis

    reinis Member

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    Hello!
    I've got only one question, don't know how incoherent it is.
    But I just want to know, which color filters increase contrast and which - decrease. And which colors - more and which - less (like - medium green - #3;
    dark blue - #5 and so on). I've never used any filters, so I don't know.
    Hope You got the idea.
    Thanks a lot!
     
  2. Ornello

    Ornello Inactive

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    Filters absorb their complements. Two colors that are close in value but different in hue (red and green apples for instance) will reproduce as a similar grey value when no filter is used. If a gree filter is used, the green apple will appear lighter and the red one darker. Using a red filter will make the red apple lighter and the green one darker.

    And so on....
     
  3. ann

    ann Subscriber

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    the filters you are quoting here are filters that are used in the field when taking the pictures.

    Because this question has been posted under the enlarging thread, i will assume that you mean the filters used with printing. These are not the same.

    You will need to purchase a set of enlarging filters. These run from 00 to 5. The lower numbers reduce contrast, the higher numbers increase contrast.

    If i have mis-understood your queston then the filter numbers you are talking about, separate gray values with black and white film. With these filters, the color used lightens that color and darkens it opposite color, which is found on a color wheel. I.E.
    A red filter will lighten red and darken blue.
     
  4. reinis

    reinis Member

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    Well, I meant the filters used with printing. Yes, I just need some two or three filters, not the whole set. So, I'll look only for those filters (colors) I need.
    So, if You know, can You tell me please what color are the #5 or #4 filters?
    Or, if I'm telling something wrong, tell me please.
    Isn't it more or lesss like this - The blue (printing) filters increase contrast, but the green ones - decrease.
    Isn't it like this? Isn't it only the matter of color?
    (Yes, I know that my wueston could look absurd or awkward)
    Thanks.
     
  5. johnnywalker

    johnnywalker Subscriber

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    Others can answer this better, but I don't think it is only a matter of colour. The printing filters I have are all shades of red/orange. I'm sure there are many types, but mine are simple plastic squares that fit in the enlarger. They are not nearly as expensive as the filters used for taking pictures, and come as a set from 00 to 5, as Ann said.
     
  6. Claire Senft

    Claire Senft Member

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    Yes when using VC paper blue increases contrast and green reduces it compared to no filter. In actual fact though the filters sets sold for printing on VC paper are Yellow and Magenta. Ypu can think of yellow as being red+green, and magenta as being blue+red. The VC emulsion is blind...has no sensitivity...to red. I would suggest that you buy a full set as I believe you will end up using all of them or buy a set of 98 and 99 filters,,,58 and 47b would be quite similar. These two filters used sequentially would allow you to create a full spectrum of grades in a stepless manner. They would not be anywheres near the convenience of a filter set. These 2 filters may not be available in acetate. You may have to buy polyester, gelatine or glass.

    I believe that Ebay normally has filter set available new. I am not conversant with the prices at camera stores or Ebay.
     
  7. ann

    ann Subscriber

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    the printing filters come in sets. At one time, one could buy Ilford filters by the sheet bt they are a 12 inch filter.

    The higher the contrast the deeper the maganta color of the filter
    What is the light source on the enlarger you are using?

    Is it a VC type? If so, this is probably why you are thinking blue and green.
     
  8. reinis

    reinis Member

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    Well, I'm from Latvia, and here it's not so simple to get anything You want from ebay or simply go to the nearest shop.
    As I said, I've never tried, so I have not used the VC paper yet, but I think it will be tura or Agfa.
    It's hard to get any Ilford stuff here now.
    The enlarger ligt source? Well, the enlarger is an old "Krokuss color 4" (made in USSR), probably the name won' tell You anything.
    But the source is either a simple matt bulb, or some kind of a little halogen bulb (with the smallestfilament).
     
  9. winger

    winger Subscriber

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    If you can buy from Adorama, a filter set is around $25 US, depending on the size and brand. It's better to get the filters from the same brand as the paper you will use, but it's not written in stone.
     
  10. ann

    ann Subscriber

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    if this is a color head enlarger. you have three dial in channels of color.
    WHen printing b&w you do not use the blue,(cyan) channel. Only the yellow and red.

    yellow will lessen the contrast, while the red , or maganta channel will increase contrast.

    the paper you use should have a chart that will recommend how much of each is needed to achieve a starting point for the contrast.

    Until you us VC paper, the filters will not be of any value.
    Graded paper does not need a filter


    If this enlarger does not have dial in filters you will need to find a set of VC filters, or as someone else suggested, a 58 or 47b filter. which has already been suggested in another reply to this question
     
  11. Bob F.

    Bob F. Member

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    Not quite.... you need two filters at a minimum. The hard (high contrast) emulsion reacts to blue light, the soft (low contrast) emulsion to green light. You use yellow filters to expose the soft emulsion (yellow subtracts, i.e. blocks, the blue from the enlarger light) and magenta filters to expose the hard emulsion (magenta subtracts green).

    In practice, filters are bought in packs of grade 00 to 5. Unless you want very large square filters, this is the simplest way to obtain them. If you can't packs for some reason, but can get individual filters, then 130 or more of yellow and 130 or more of magenta should get you going (based on the maximum yellow and magenta on my enlarger's colour head which I use for this method).

    You then vary the amount of hard/soft emulsion exposed by varying the amount of time the paper is exposed through each filter. Do a search here on APUG for "split grade" and "split filter"

    Cheers, Bob.
     
  12. reinis

    reinis Member

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    Thanks a lot, I think I got the idea.
    Actually the enlarger isn't meant to be used with any filters (any size), so it's not that important.
    And since I'm a total amateur, I don't need nor a set of 100 filters.
    Well, the situation is like this: the enlarger uses the same lenses as my old Zenit cameras (with the M39 or M42 thread).
    So, can I use the color filters that are used in the field when taking the pictures?
    They are glass filters, and I have got green, yelloy and blue ones.
     
  13. lee

    lee Member

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    Reinis,
    go to darkroomagic.com and under the "Book" heading you will find a listing for basic split grade filter printing. it is a .pdf file so you will need Adobe Acrobat and read all that and it should give you the answers for the questions you are asking.

    lee\c
     
  14. reinis

    reinis Member

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    Ok, thanks, I'll try that.
     
  15. ann

    ann Subscriber

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    if you are attempting to do split printing check
    www. darkroomagic.com
    there is some information there that might help you
     
  16. ann

    ann Subscriber

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    you don't need 100 filters.
    you need a basic box that contains a total of 12, starting with 00 and increases in 1/2 steps.
    You can't use the same filters for printing that you use for making pictures, even it the lens is the same as the camera lens.

    THe paper will not response to those filters, they need a special set that is made for controling and changing the contrast with the paper.
     
  17. Bob F.

    Bob F. Member

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    In a nutshell: probably not. They will probably be much too feint, allowing too many other wavelengths of light through. I take it that your enlarger does not have a colour head? If not, I'm afraid you will have to find some filters from somewhere and, if it does not have a filter drawer, you will also need an under-the-lens filter holder too...

    You still have the option to use graded paper but that will mean buying several different packs to cover grades 1 - 4. Or try grades 1, 3 and 5 to reduce costs, aiming to print on grade 3 for a "normal" negative. There are tricks you can do in the darkroom to get the intermediate grades, but frankly, as a beginner, use VC paper and get some proper filters - it will make your life so much easier. Only 6 or 12 filters in a pack, depending on maker (and if you use split-grade printing you only use the grade 00 and grade 5 ones).

    Good luck. Bob.
     
    Last edited by a moderator: Apr 13, 2005
  18. johnnywalker

    johnnywalker Subscriber

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    Not red/orange?? Good thing I don't try and take colour pictures. Also a good thing the filters have those little numbers on them! :rolleyes: :D