You take a photo. The light may be a bit to bright. How do you control it with the least bit of effort in Photoshop? Quite easy. Use a desaturated layer.
Step 1 : Open your image in Photoshop. I have opened a free stock image.
Step 2 : Press CTRL+J twice. You will notice that the Background layer triplicates into Layer 1 and Layer 1 copy.
Step 3 : Click on Layer 1. Press CTRL+SHIFT+U. The layer is desaturated.
Step 4 : Click where the red arrow points to, to bring up the Blend Modes and click on Multiply.
And, there is the difference. It was easy was it not? Try other Blend Modes as well. It may be suitable for your image.
This is how it looks with Hard Light. You can try the Blend Modes. Settle on which suits your image.
Other tutorials are here.
