Masking a photo for lights and darks

[Emily Ruiz]

Hi, I am trying to make a mask out of a black and white photo. What I ultimately want to do is have the darks be one color and the lights be another color, similar to this photo where the darks are orange and the lights are blue but there is still detail and range. I want full control over what the base color is though and I'll be treating different photos, so I don't want to use too many blend modes if possible. My thought was if I can separate the light values and dark values through masking (one that focuses on black as masked and the other is just inverted) that could get the desired effect.. but how do I do that? Would appreciate any tips or if there is another approach, that's great too. Thanks!

[George_F]

I would guess this is color graded possibly with the opacity adjusted.  Try a gradient map adjustment layer.  No mask required for your desired effect, just choose the two colors for the gradient, orange on the dark side and teal on the bright side.  

This could also be a LUT using a color lookup adjustment layer.

I'm sure there are more ways to achieve this, those are just the two that come to mind for me.

[PBArtattack · Accepted solution]

Another way would be to use Channels and two Solid Color (Color Fill) adjustment layers. (If your image is Grayscale, convert it to RGB.)

Go into Channels and Control-click on the RGB icon. This will make a selection of the lights. Copy it (Control + C). Open a Solid Color adjustment layer, select your dark color, then paste (Control + V) the Channel selection into the mask.

Temporarily turn off the adjustment layer, go back into Channels, Control-click on the RGB icon again, and then invert the selection (Control-Shift-I) to make a selection of darks. Copy it. Open a second Solid Color adjustment layer above the first one, select your light color, and paste the new Channel selection into its mask.

What's nice about this is that it's easy to switch out colors.

It might help if the original image were a bit on the contrasty side.

[D Fosse]

I'm with George: gradient map. This is a textbook case for it.