The Color Correction Discussion

Discussion in 'General Mac Discussion' started by arn, May 26, 2003.

  1. arn macrumors god


    Staff Member

    Apr 9, 2001

    I recently got a film scanner - in order to scan a lot of negatives I have.

    In doing so, I realized I needed to pick up some color-correction skills.

    In doing some basic research, I came across Professional Photoshop: The Classic Guide to Color Correction.

    I realized this was a bit overkill... but figured it was well reviewed.

    Anyhow... I'm still learning... and will likely be reading this book over and over. Does anyone else have any good resources or tips?

  2. Eniregnat macrumors 68000


    Jan 22, 2003
    In your head.
    I don't know what I can add to this, as I am not a Photoshop guru, demi-god or hoar. I found this site which looks like a good place to start. Well nobody else has chimed in, so here's what I have to write.

    Trial and error and your work is only as good as your tools.
    First, for just about 15 years my family owned a custom photo lab until it went belly up. (A happy and sad event.) During that time we watched the photographic world change for the better (digital) and for the worse (digital and APS). As another side note, and why scanning your negatives is important, some paper manufactures (just one) actually guaranteed that customers would come back with in 11 years because the paper was designed to degrade over that time, another company hinted the same about the film emulsions that they used on their negatives.

    The Adobe app for adjusting you monitor is great. Use the Adobe app to create your Color Sync profiles.

    As far as calibrating your monitor, if you don't have calibrating hardware load up a picture with known values and eyeball it. If your scanner came with test picture in hard and digital form then load the digital picture, sync the image and then scan the image, and adjust your scanners settings (if you want). The hard copy test image will age and most people that deal with photographs on a regular bases get new test set (digital, negatives, and prints) every three months.

    Beyond the calibration of your equipment, all I can say is what looks good for you. I would guess that you’re using software that makes a positive from the negative, so that's a start. In some sense I would say leave your scans in their native and original form, because you can always adjust from there. For individual projects, just try to see what looks good to you. There are probably lots of people out there that will give better advice, but ultimately, what looks good to you (unless your color blind). The photographic world is filled with the same kind of people that complain about the wrong kind glass for a particular wine or roll their eyes at a $9.00 bottle of wine from Santa Barbara or lower Napa. In the end, what looks good to you and what are you after?
  3. trebblekicked macrumors 6502a


    Dec 30, 2002
    Chicago, IL, USA
    Re: The Color Correction Discussion

    a couple questions:

    are you using multiple displays?
    LCD or CRT?
    All same brand/make?
  4. beatle888 macrumors 68000


    Feb 3, 2002
    thats the best book for the topic IMO.
    closed calibration is the way to go. i work in the printing industry and even our top vendors dont use colorsync. mainly because you cant rely on everybody to obey the rules.

    closed calibration is when you know your final output device. so you take a file with lots of neutrals, and output the file to the final device. then you take that hardcopy output and compare it to the digital file on your screen. now you need to adjust the color of your monitor to match the neutral areas in the hardcopy. your not going to nail it but you can get close.

    the next thing to do is read up on using the info pallet in photoshop. i use the target eye dropper tool to select a highlight midtone and shadow, plus one in the flesh tones if any. once you have all your target points placed with the eyedropper tool you can use your info pallet to read their values as you make adjustments. for cmyk a good highlight would be 5c3m3y0k, the darkest shadow with detail depends on the output device but 65c53m52y95k is standard. the midpoint is tricky, you just need to shoot for a neutral mix of ink (if you want to remove all color cast) which i believe is generaly 10% more cyan than m-y, while m-y are about the same (usually a touch more magenta than yellow). so if you had 40c28m26y10k that would be pretty much neutral. its up to you to decide if the image is to warm or cool. if its too cool that bring the cyan down and add some magenta and yellow.

    the book you chose covers what i just said. once you know how to manipulate the curves and use the info to keep an eye on your values, you'll do fine. also, the auto color in photoshop 7 seems to work pretty good for most images. and remember, if you want color to POP, increase the contrast in the unwanted color. in other words. grass in green, so the unwanted color would be magenta. so increasing the contrast in the magenta channel will remove the magenta from the midtones and highlight while adding magenta to the shadows, this will increase the detail and really clean up the image. say you have a nice shot of some desert canyon rocks, but they just dont POP, go into the unwanted color channel (through the curves tool) and increase the cyan contrast...BAM. nicely defined rocks that are clear and natural in color. you can do color correction in your scanning software as well, most likely the tools will work the same.

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