Photoshop/lightroom question

Discussion in 'Digital Photography' started by soup4you2, Jan 10, 2008.

  1. soup4you2 macrumors regular

    Apr 12, 2007
    Just curious how this is done. I'm pretty new to both these tools.

    I have a color photo that i would like to make black and white. except for 1 color. lets say red. in lightroom (preferably) or photoshop how could i accomplish this?
  2. Lovesong macrumors 65816


    Sep 15, 2006
    Stuck beween a rock and a hard place
    Not sure about lightroom (it's probably easier than what I'm describing, but I use Aperture), but in PS, open an image, press apple-option-shift-b (or go image > adjustments > black and white. You can then use pre-set filters (like b&w with red/blue filter) or adjust a handful of channels separately.
  3. M@lew macrumors 68000


    Nov 18, 2006
    Melbourne, Australia
    Photoshop has a much better and more accurate way of doing this. Lightroom would just consists if dragging the saturation sliders all the way to the left except for the colour you want. Problem with this is that should you have small hints of the colour in the photo they'll still show.
  4. Edge100 macrumors 68000

    May 14, 2002
    Where am I???
    Are you interested in spot colour (i.e. only one thing in the image is in colour) or are you interested in having all of the reds in the entire image show up?

    I'm only familiar with the former (though I'm sure the latter could be acomplished with selective desaturation), so here's an easy way to do spot colouring. Since you have a colour photo to start with, it's fairly easy (in PS...never tried in it LR):

    1. Convert to B&W using a layer-based method; in PS3 you have some nice presets in the Channel Mixer. Whatever you do, do NOT simply convert the mode to greyscale.

    2. Now expose the colour in the BG layer by "painting" away the layer mask on the Channel Mixer layer (which you created in step 1) to expose the colours underneath. Anything you paint black with show through, anything with white will not. Shades of grey will allow progressively less or more of the BG colour.

    It's a great technique, if used appropriately (i.e. not too often).
  5. qtpie36963 macrumors member

    Jan 9, 2008
    Here's a really simple step by step approach that works very well!!

    Using PS CS3 (but would work with any photoshop)....

    1) Select the Magic Wand tool.
    2) Click on the area you want to keep (for example the red section)
    3) If it doesn't select the whole area you want, hold down the shift key and continue to select the area you want to keep red. (You can do this as many times as needed as long as you always have the shift key down everytime you click)
    4) Once you're satisfied with your selected area go up to the SELECT menu and select INVERSE
    6) Take down the saturation.

    Hope that helps... it's really easy. I just tested it with one of my photos and it took about 2 minutes tops!

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