Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,727   Posts: 1,515,142   Online: 1099
      
Page 3 of 3 FirstFirst 123
Results 21 to 28 of 28
  1. #21
    2F/2F's Avatar
    Join Date
    Apr 2008
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    8,008
    Images
    4
    "I understand color, just not exactly how these dichroic heads work. And I know independently they work opposite of each other. So does that mean that in reverse they will produce RGB spectrum onto paper once it's printed and processed?"

    I do not understand that paragraph at all.

    Three additive primary colors of visible light are red, green, and blue. Their complements, respectively, are cyan, magenta, and yellow; the colors of the filters in a color head. These complements to the additive primaries are also called subtractive primaries. You can look at this picture from Wikipedia for a graphic representation of exactly what I just said: http://upload.wikimedia.org/wikipedi...eColor.svg.png.

    The most basic principle beyond this is that whatever you do to filtration has the opposite effect on the print (when using negative paper, of course).

    Magenta filtration controls magenta and green casts.

    Yellow filtration controls yellow and blue casts.

    Cyan filtration controls cyan and red casts.

    Any time you stack three transparent primary filters in the same amount, you get a neutral grey filter. Thus, whenever all three filters are in use, there is neutral density added in the amount of the lowest filter. Therefore, there is no point in using three filters, unless you "run out" of one of the other two.

    Equal amounts of green and blue equal cyan, therefore changing magenta and yellow filtration in equal amounts has the same effect as changing cyan filtration. (Of course, the difference is that turning UP cyan filtration makes the print more red, while turning DOWN equal amounts of magenta filtration and yellow filtration makes the print more red.)

    Work backward from the print. First, get a rough density at a "normal" filtration. Then, figure out what is wrong with your print color wise. If print has too much of a certain cast, your goal is to add the complement of that cast to the print. You know that the opposite of what you want to done the print, you want to do to your filter pack. Since your goal is to add the complement of the cast to the print, you must subtract that complement from your filter pack OR add the color of the cast itself to your filter pack; it's the same thing. Thus:

    If your cast is red: You need to add cyan to the print. Therefore, you need to subtract cyan from the filter pack. Since you are using the two warm filters only, put "subtract cyan" into "warm" terms: "add red". Equal amounts of magenta and yellow equal red. Thus, when you have a red cast, add equal amounts magenta and yellow filtration to the filter pack.

    If your cast is magenta: You need to add green to the print. Therefore you need to subtract green from the filter pack. This is the same thing as adding the compliment of green to your filter pack. Thus, when you have a magenta cast, add magenta filtration.

    If your cast is yellow: You need to add blue to the print. Therefore you need to subtract blue from the filter pack. This is the same thing as adding the compliment of blue to your filter pack. Thus, when you have a yellow cast, add yellow filtration.

    If your cast is green: You need to add magenta to the print. Therefore you need to subtract magenta from the filter pack. Thus, when you have a green cast, subtract magenta filtration.

    If your cast is blue: You need to add yellow to the print. Therefore you need to subtract yellow from the filter pack. Thus, when you have a blue cast, subtract yellow filtration.

    If your cast is cyan: You need to add red to the print. Therefore, you need to subtract red from the filter pack. Equal amounts of magenta and yellow equal red. Thus, when you have a cyan cast, subtract equal amounts magenta and yellow filtration from the filter pack.

    You should be able to spot at least one basic trend in all of this that you can use as a shortcut: If the print has a warm cast, you must add filtration. If the print has a cool cast, you must subtract filtration. Thus, when using just magenta and yellow filters (both of which are warm filters), you always add filtration to cool a print and subtract filtration to warm it.

    This would not hold true in all cases if you were using cyan filtration; yet another reason to leave that knob alone unless you min. out on one of the other filters.

    Filters will have the same affect on the cast of your prints any time you are using a color negative paper, regardless of film, process, etc. This includes cross processed film. The film is different, but the effect of filtration changes during printing is the same.

    The hard part is identifying what each cast *actually* looks like (not just what it *sounds like it looks like*), and honing in on "in-between" casts. For instance, a blue cast looks purple, not blue. A magenta cast looks pink. A red cast looks kind of muddy; not red like you would imagine. A color cast is almost never just one or the other. The "art" comes in employing casts to achieve, amplify, or minimize various moods and effects without making them look "bad".

    ...but if you "understand color" are getting perfect prints, you know all this already, and printing your cross processed shots to the best color you can achieve should be easy as pie for you. Everything I just talked about is first-day stuff in a color printing class or color photo book. I recommend both of these, as it sounds like you need them, and they will give you far more info we can on the Internet.
    Last edited by 2F/2F; 05-12-2009 at 05:10 AM. Click to view previous post history.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

    - Rob Tyner (1944 - 1991)

  2. #22

    Join Date
    May 2005
    Location
    Woonsocket, RI USA
    Shooter
    35mm
    Posts
    2,725
    Quote Originally Posted by fiducio View Post
    So the basic model is that adding Cyan will give more Red, Magenta more Green, and Yellow more Blue, right?
    Yes, but I prefer to think of it this way: The "cyan" dial controls the cyan/red balance, "magenta" controls the magenta/green balance, and "yellow" controls the yellow/blue balance. It's a bit of a subtle distinction, but for me it makes the whole think click. Combine that with a ringaround that adjusts all three colors up or down and finding a good color balance becomes much easier.

    FWIW, my own enlarger (a Philips PCS130 with PCS150 color unit) actually has those pairs (cyan/red, etc.) marked on the color controls. This is a very useful tool. If I get a print that's obviously too green (say), I can look at the control and just plain see which way I need to turn the dial to make it less green (aka to make the print more magenta, which means less magenta filtration).

    And what I'm asking is when C=0, no Cyan is making it through from the head, right?
    No. Cyan is the combination of green and blue light, and a cyan filter blocks red light, but leaves green and blue. When the cyan filter is set at 0, it means that the cyan filter is out of the light path, so all the red light the bulb is putting out is reaching the paper. The levels of green and blue light reaching the paper are determined by the magenta and yellow filters, respectively. Even when set to its maximum, the cyan filter won't affect the amount of green and blue light reaching the paper (in theory; in practice there'll be a small effect, since no filter is perfect in a theoretically abstract way). When set to maximum, the cyan filter will block most of the red light from reaching the paper.

  3. #23
    fiducio's Avatar
    Join Date
    Apr 2009
    Location
    Tahoe, CA
    Shooter
    Medium Format
    Posts
    153
    Images
    6
    Alright, I'm sorry for sounding pretentious. :[

    Thanks for clarifying though, and what I did think was right, I just realized how these colorpack filters work. Thanks a lot!

    I do plan on taking a color printing class of some sort, but there will not be any classes in a few months. I'm on my own for now.

    And yes, that color chart is what I understand, it was in the dark room I realized I had to work inversely from that model. White=Black, Red=Cyan, etc. And my thought was since the orange filtration from the normal C41 cast was gone, I would have to lower my magenta and yellow and throw cyan in there. But I was terribly wrong. :]

    At least I'm learning from my mistakes, and realizing I'm going to have to throw in as much Yellow+Magenta as possible next time!

    I'm learning, and I'll keep working. I'll report what happens saturday!

  4. #24
    2F/2F's Avatar
    Join Date
    Apr 2008
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    8,008
    Images
    4
    Quote Originally Posted by fiducio View Post
    And my thought was since the orange filtration from the normal C41 cast was gone, I would have to lower my magenta and yellow and throw cyan in there.
    If the orange mask is gone, warmth is removed from the filtration. The opposite happens to the print, so it warmth is added to it. You would have to subtract warmth from the print to make up for it. To subtract warmth from the print, you must add warmth to the filter pack.

    Or, more simply, the orange mask being gone takes away orange, and you need to add orange to make up for it.

    The way I approach orange casts is to add both magenta and yellow filtration, with yellow added in twice the amount of the added magenta. For instance, if I decide I have a 20-point orange cast, I might start by adding 20M and 40Y.

    Cyan need not be touched unless you run out of magenta and/or yellow, or unless you want to dial in very precise amounts of neutral density. Cyan works opposite the other two filters, since it is cool and the other two are warm; another reason not to use it.
    Last edited by 2F/2F; 05-12-2009 at 05:11 PM. Click to view previous post history.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

    - Rob Tyner (1944 - 1991)

  5. #25
    fiducio's Avatar
    Join Date
    Apr 2009
    Location
    Tahoe, CA
    Shooter
    Medium Format
    Posts
    153
    Images
    6
    Thanks a lot 2F/2F, I'll attempt the same print.

    I'll keep these as basic guidelines when I'm printing again, you've helped quite a bit. And answered my questions very thoroughly. :]

  6. #26

    Join Date
    May 2005
    Location
    Woonsocket, RI USA
    Shooter
    35mm
    Posts
    2,725
    Quote Originally Posted by 2F/2F View Post
    Cyan need not be touched unless you run out of magenta and/or yellow, or unless you want to dial in very precise amounts of neutral density. Cyan works opposite the other two filters, since it is cool and the other two are warm; another reason not to use it.
    FWIW, on my enlarger, I require cyan filtration, along with increased magenta and yellow, because without that my printing times are too low, even with the lens stopped all the way down. I also like to start with some cyan because that makes printing a complete color ringaround a bit easier; I can subtract 5 or 10cc of cyan rather than add 5 or 10cc of both magenta and yellow.

  7. #27
    fiducio's Avatar
    Join Date
    Apr 2009
    Location
    Tahoe, CA
    Shooter
    Medium Format
    Posts
    153
    Images
    6
    Nevermind, I already know. :P
    Last edited by fiducio; 05-12-2009 at 09:19 PM. Click to view previous post history.

  8. #28
    2F/2F's Avatar
    Join Date
    Apr 2008
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    8,008
    Images
    4
    FWIW, I had to employ cyan filtration for the first time ever today. The electronic Beseler color head I was using does not let yellow and magenta go below a certain level, so I had to add cyan to lower the Y and M numbers. Even though I turned up the cyan knob, the only thing it did was lower the numbers for Y and M. The cyan LCD stayed at zero.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

    - Rob Tyner (1944 - 1991)

Page 3 of 3 FirstFirst 123


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin