Color Correction References

Discussion in 'Color: Film, Paper, and Chemistry' started by markbarendt, Dec 11, 2009.

  1. markbarendt

    markbarendt Subscriber

    Messages:
    7,508
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    I've just started RA-4 printing from C-41 negatives and have been giving some thought to getting the color nailed.

    The need for this really hit home when I switched from 160NC to Superia 400 mid-print-session earlier this week.

    I really already knew I needed to do something along this line because I enjoy shooting some with a Holga. (She's my first and her name is Helga :smile: )

    I'm now planning to shoot a frame on each roll with a grey card; actually a black, white, and grey card set I have already.

    The other thought I had here was leaving one frame unexposed on 135 or using some of the unexposed leader of 120.

    So my questions:

    1 - Can any of this be judged during "focusing"? (i.e. Can I see this on the paper in the easel before exposure?)

    2 - Is a blank frame valuable say to judge the basic color correction for the roll and find max black or is the "grey card shot" plenty?

    3 - Are there other tricks to make this quicker and more accurate?

    Thanks
     
  2. mopar_guy

    mopar_guy Subscriber

    Messages:
    1,177
    Joined:
    Sep 12, 2009
    Location:
    Washington,
    Shooter:
    Multi Format
    Look for a Macbeth color checker card to photograph one exposure per roll.
     
  3. rthomas

    rthomas Member

    Messages:
    1,182
    Joined:
    Jan 2, 2009
    Location:
    Charlotte, NC, USA
    Shooter:
    35mm
    Look for a Kodak Color Print Viewing Filter Kit - this, along with a daylight light source, will give you a pretty accurate way to judge the color balance of your prints (especially if you have the Macbeth color checker printed for a particular film).
     
  4. Mike Wilde

    Mike Wilde Member

    Messages:
    2,936
    Joined:
    Aug 10, 2006
    Location:
    Misissauaga
    Shooter:
    Multi Format
    Colour checkers, even the little ones meant for digital can be pricey. Scour the web or camera shows etc. for an old color darkroom data guide from Kodak. They include a test swatch page of clour chips opposite the page of grey card stock.

    One shot per type of film, per lighting situation is usually enough for me of a such a color swatch.
     
  5. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
    Highly unlikely just "by eye", as the color mask on the film and the reversed colors will throw you off. This is possible with a color analyser, but you need to calibrate those to printing results.

    The blank frame will tell you about the film, but the grey card shot will tell you about balancing for the light source used for a given shot. Those aren't the same thing, and the grey card negative is the one to use to judge color balance.

    The print viewing cards already mentioned can be very helpful, but judge by a mid-tone with them, not a bright highlight or deep shadow.

    You might be able to find a used color analyser for printing. These should be pretty cheap these days. They like a known target like a grey card.

    If you can't afford an Xrite/Greytag/Macbeth ColorChecker, try paint chips or formica samples from your hardware store. Some paint chips show a nice gray scale, and you can take your grey card in to help find the most neutral. However, the reason that the ColorChecker is so expensive is that the pigments used are not subject to weird color renditions under widely varying lighting conditions (sun, shade, tungsten, fluorescent, flash, etc). Many pigments and dyes shift their appearance radically under different light sources and can throw you off. Whites often have optical brighteners that throw you even further off. So you'll need to see if any cheap substitute actually works as needed.

    Lee
     
  6. Greg Davis

    Greg Davis Member

    Messages:
    2,057
    Joined:
    Feb 4, 2004
    Location:
    Nicholasvill
    Shooter:
    8x10 Format
    The light you view the print under can change how you color balance, as well. There are very expensive light units to use, but Kodak recommends a pair of fluorescent lights with "Cool Deluxe White" bulbs and if you want a mix of daylight and tungsten like a gallery with big windows, add a 75W flood light for every pair of fluorescent bulbs. Make sure you only view the dried print. A wet print will have a different color appearance.
     
  7. hrst

    hrst Member

    Messages:
    1,300
    Joined:
    May 10, 2007
    Location:
    Finland
    Shooter:
    Multi Format
    First, about balancing; I find that the experience with color printing will be your best guide! I have not used any special means to balance, just my eyes at the final print, making some test sheets. And I've wrote down starting filtrations for different films & shooting conditions. You can make a table like this:

    --------- Tungsten light -- sunlight ... etc.
    Film1 ----- xx M xx Y ---- xx M xx Y
    Film2 ----- xx M xx Y ---- xx M xx Y
    Film3 ----- xx M xx Y ---- xx M xx Y

    etc.

    Now, after two years of occasional printing, maybe a hundred sheets, I can guess the correct filtration very close and make the final correction usually after one test sheet. So, just take your time.

    Yes, you can use unexposed frames to balance for the orange mask, but why bother, as you can take an actual picture and do the same balancing and get a picture, not just gray frame.

    And remember, the light when shooting matters. If it's cloudy or sunny or if it's taken indoors... The colour temperature differs quite much ranging from 2500K to 9000K. That's a huge difference in balancing (from about 80Y to 190Y on our Fujimoto, plus some magenta tweaking).

    Then, about viewing the prints;

    There is a very common disinformative belief (initiated by the marketing staff of daylight lamps) that you need a "daylight lamp" to evaluate your prints, but that's 100% bullshit for two reasons:

    1) It tells (or it SHOULD tell...) you what the print looks like in daylight-balanced light, but what do you do with that information if the print is not viewed outside in the sunlight? The only correct color temperature for print evaluation is the same type of light source where the final print will be viewed! It may be sunlight, but at home, it's usually 2800...3200 K tungsten, and in galleries it can be 3400K tungsten ---- all very far from "daylight lamps"! Or it may be some combination of sunlight and artificial light.

    2) There is NO decent fluorescent "daylight". Fluorescents have no color temperature at all, it's all marketing. The best ones can be quite close but not quite and they are expensive.

    SO, when evaluating your prints, try to use the same type of illumination than where viewing the final prints. Probably they will be looked at all kind of color temperatures, so this game has been lost from the beginning and you don't have to stress so much about the color of evaluation light. The eye has incredible tendency to balance automatically.

    Combining different types of light is actually quite a good idea. You can even have them in different directions so you can see the effect when moving your print.
     
  8. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
    Fluorescents do have a sometimes 'spiky' spectral output. But they are referenced to a color temperature (CCT) standard, with a color rendition index (CRI) that ranges up to 100 for perfect visual color rendition. You can get GE Chroma 50 or Philips C50 fluorescent lamps for a typical 4 foot shop light or ceiling fixture. The Chroma 50 has a CRI of about 90 or 91, and the Philips C50 has a CRI of 92 with reference to a 5000K daylight CCT standard. Both of these would meet industry standards for judging color balance by eye, which is what they are designed for. They are also designed by lighting engineers, not marketing divisions.

    As mentioned earlier, human vision compensates for viewing conditions, but evaluating prints for general use can be done very well under high CRI fluorescents.

    Last time I checked, the Philips C50 was under $5 for a 4 ft fluorescent tube at Home Depot in the US, where the OP lives. A shop light and two 92 CRI Philips lamps would be about $20 at Home Depot.

    Lee
     
  9. Neal

    Neal Subscriber

    Messages:
    1,617
    Joined:
    Dec 3, 2004
    Location:
    Chicago, Wes
    Shooter:
    Multi Format
    Dear Mark,

    Two items I find useful are the already mentioned color filter viewing kit and the ring-around in the Kodak color Darkroom Dataguide. Lee filters has a good viewing kit available from many of the APUG sponsors. The Dataguide can be found used through Amazon quite easily.

    Neal Wydra
     
  10. Greg Davis

    Greg Davis Member

    Messages:
    2,057
    Joined:
    Feb 4, 2004
    Location:
    Nicholasvill
    Shooter:
    8x10 Format
    I should add to my post that you need to consider where your photos will be seen. If you only show them at home, look at them under your house lights. I print for exhibition, so I use Kodak's guide to give an average gallery lighting situation. Most galleries have large windows with cool daylight and add spot lights to the artwork. This is what I print for, in general. And I use the color viewing filters because I have one eye that sees cooler than the other. This prevents me from just eye balling the print color.
     
  11. Lee L

    Lee L Member

    Messages:
    3,247
    Joined:
    Nov 17, 2004
    Shooter:
    Multi Format
  12. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,771
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    A lot of your printing "problems" will depend on whether you are using Endura or CA papers. CA papers are harder to print from Kodak films than Fuji films, but Endura papers are less difficult to switch back and forth.

    I have made the same switch as described in the OP and also included Gold 400 in the mix. The biggest change was the Gold 400 which was shot with electronic flash, while the Fuji and Kodak (400 and 160) films were almost identical when shot with daylight.

    A color checker is invaluable though to judge the overall color. It has gotten to where I can judge the roll just by looking at the negative of the checker on a light table. The neutral scale tells me a lot. Of course, comparisons of neutral scales are quite useful, as is the use of a bluish filter to filter out the mask.

    PE
     
  13. markbarendt

    markbarendt Subscriber

    Messages:
    7,508
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    Wow, thanks all! I need to read and digest it now.
     
  14. markbarendt

    markbarendt Subscriber

    Messages:
    7,508
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    Okay,

    I've got viewing filters on the way and I think I have something I can use as a color card. I do like the paint chip idea!

    I do also have an electronic color checker/exposure meter (model D200/MP160/CS3) that I could use to judge prints with a bit of imagination but I'm not after that kind precision or a workflow that involves an electronic judge.

    I should probably clarify that when I say I want to "nail the color", it just means I want to get "control of color and exposure" quickly. I am in no sense trying to match a technical specification for any print. All I want is a print that looks good when it is hung, using my eyes as hrst suggested.

    I'm probably going to do a "ring around" once I get a good print too.

    As the darkroom comes together better I'll be adding the shop lamp with the nice bulbs.

    Also as suggested I'll be coming up with a chart for each film to get me in the ball park.

    Part of my challenge though is that, probably like may of us, the systems I'm using aren't necessarily "consistent". Sure, my RB and Nikons will give me consistent exposures but "Helga" won't and then I hand process my C-41 films in small tanks, in an a homemade water bath; I'm careful but this is not exactly going to give me the 100F +/- .5 that the directions call for every time and even though I have an agitation regime, the agitation of the film is directly related to my agitation (or lack thereof) at the moment.

    Good info on the paper differences too PE. I'm actually using Arista paper right now to get the concepts down because it's so inexpensive. I do like the idea of using a more forgiving paper.

    Going forward, even though the consensus seems to be that judging color during focusing is hard or impossible I'm going to experiment with that idea some too.

    What I'm looking for right now is simply ways to be able to adjust quickly and you have all been quite helpful so far. Thanks :smile:
     
  15. Bob Carnie

    Bob Carnie Subscriber

    Messages:
    5,412
    Joined:
    Apr 18, 2004
    Location:
    Toronto-Onta
    Shooter:
    Med. Format RF
    Mark

    The single best method is to have a colour wheel chart in your viewing room and a mounted ringaround chart to help you see colour.
    After thirty years of colour correcting in all types of labs I can tell you the best , and I mean the best printers have and will refer to a ring around once in awhile to refresh their eyes.
    Most colour inbalances are a combination rather than a single colour adjustment and having this ring around helps tremendously .

    I have one being designed to print out that I can tube you and any others interested in the new year. It is being prepared for photoshop courses I am teaching but is totally viable for your situation.
    There will be a fee for this but it would definately be a handy dandy piece of gear for those workers struggling with colour correction on an enlarger.


    Bob
     
  16. DanielStone

    DanielStone Member

    Messages:
    3,107
    Joined:
    Dec 30, 2008
    Location:
    Los Angeles
    Shooter:
    Multi Format
    hey bob,

    just out of curiosity, what's the largest negatives you guys are able to print from?

    thanks

    -Dan
     
  17. Bob Carnie

    Bob Carnie Subscriber

    Messages:
    5,412
    Joined:
    Apr 18, 2004
    Location:
    Toronto-Onta
    Shooter:
    Med. Format RF
    11x14 on Black White only for colour we scan and lambda
     
  18. markbarendt

    markbarendt Subscriber

    Messages:
    7,508
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    Great thought Bob, Wikipedia had a wheel or two I could print on my laser.

    Ring around is next.
     
  19. tim elder

    tim elder Member

    Messages:
    147
    Joined:
    Oct 9, 2005
    Location:
    New York, NY
    Shooter:
    Multi Format
    Something I would suggest is to not switch film stocks during print sessions; or, if you do, be prepared to make changes. Every stock is slightly different and requires a different filter pack. Even going from Kodak VC to Kodak NC creates a need for a different filter pack. To go even further, examine your negatives and your guide prints (if you have any) and group negatives with similar lighting conditions together when you print. I find that it helps to examine my negative before I put it in the enlarger and I do look at it while I'm focussing it as well, but I think that this helps more with judging densities than color balance.

    Tim
     
  20. Bob Carnie

    Bob Carnie Subscriber

    Messages:
    5,412
    Joined:
    Apr 18, 2004
    Location:
    Toronto-Onta
    Shooter:
    Med. Format RF
    good advice

     
  21. markbarendt

    markbarendt Subscriber

    Messages:
    7,508
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    Not switching mid-session is a good idea but I do also want to use up the chemicals. I'm going to work on designing a setup for each film base.

    One thing that I'm having fun with lately is my Holga and printing contact sheets as the finished print. So no I don't group densities I just take it as it comes.