Fixing Images with Contrast Masks in Photoshop
Many of the fixes we commonly apply to images come from darkroom processes. Contrast masking is one of those fixes and it can be used to fix an image which is under or over exposed.
Contrast masking is a relatively simple process and it can work wonders with your images. I like it because it generally doesn’t require you to make selections and there is a lot to like about fixes that don’t involve selections.
Here’s how to use Contrast Masking to fix an under exposed image:
Open your image and duplicate the background layer. Target this duplicate layer in the Layers palette.
Desaturate this layer by choosing Image > Adjustments > Desaturate. Right now the default convert to black and white is just fine.
Alter the blend mode of this layer to Overlay.
To invert this black and white layer choose Image > Adjustments > Invert – this gives a negative of the image.
Adjust the layer opacity to suit.
Convert the top layer to a Smart Object by choosing Filter > Convert for Smart Filters.
Now blur this layer by choosing Filter > Blur > Gaussian Blur. Adjust the Radius to adds some sharpening back to the image. Check the preview to get the best result for the image.
10 Responses to “Fixing Images with Contrast Masks in Photoshop” - Add Yours
December 5th, 2012 at 11:47 am
Interesting technique Helen. Never tried it that way before. I tend to rely so much on filters when I’m in a hurry!
December 6th, 2012 at 12:26 am
sorry but i like the before picture more . Like my Dad always said ..IF IT AINT BROKE DONT FIX IT …now i know what hes saying …this is one of those times
December 6th, 2012 at 12:42 am
This seems to be do-able in other software too. I use the GIMP, will try this over the weekend. Thank you very much
Just a question: How important is the ‘Convert to Smart object’ step? Can this be used by adding gaussian blur without converting to smart object?
December 6th, 2012 at 2:30 am
Hi @Jeet – you raise a good point and some other readers have emailed me direct to ask the same question. The answer is not at all – you can do it without converting to a smart object – the only issue will be that you can’t alter the blur later on if you don’t have the filter applied to a smart object layer. But if you leave out that step, this can be done in GIMP or Photoshop Elements for example and work similarly.
Cheers
Helen
December 6th, 2012 at 2:53 am
Ya I don’t see any benefit converting to smart Object either.
December 6th, 2012 at 5:04 pm
Thanks Helen, now I’m just waiting for the weekend and free time to test this out
There might be a workaround for altering the blur later:
I would duplicate the top layer a few times, and apply different levels of blur to each duplicated layer keeping one untouched for future use. Then each of the new layers can be made visible one at a time to check out the effect of different levels of blur. If saved in the native format (.psd for Photoshop, .xcf for the GIMP) it keeps the layers intact, and jpgs can be exported with the desired blur level as and when desired. The one layer without blurring can be used to try out further levels of blur, or maybe even other effect. This way, you can even use more than one blurred layer with different opacity/mode for different effects.
December 6th, 2012 at 6:28 pm
Is this “Contrast Masks” one of the ways to lighten a pic? Is there a difference when I use Exposure and Sharpen in Lightroom 4?
December 7th, 2012 at 8:34 am
thanks
why can’t we see a decent before/after or at least final result?
come on! 250×160 pixels?
December 8th, 2012 at 5:13 am
This is a great technique and in a certain way works like Shadow/Highlights filter. The additional flexibility is in using slightly different mask. For example, try blurring with Smart Blur or Surface Blur instead of Gaussian. The other trick I like to use is not desaturating the picture. Instead you can use the Hue/Saturation adjustment and lowering the saturation to -50 and at the same time shifting the hue by 180.
All of this is possible with other software, not just Adobe Photoshop.
December 11th, 2012 at 6:03 am
@ali: That’s a good point.
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