Masking!! One of the many reasons I can’t live without Photoshop. A lot of people think masking is complicated but it’s really a pretty easy concept. All you need is a layer of some sort with a mask and a brush to paint on the mask. A mask sits next to your layer and depending on whether it’s a white or black mask, it will reveal or conceal your layer. White reveals and black conceals. Your brush can also be black or white and will reveal or conceal as well. Layer masks work in black, white and the shades of gray in between black and white. They do not work in color. White means 100% visible, black means 100% transparent and depending on the shade of gray you are using it will be some level of transparency.
Let me illustrate below.
Here is my SOOC (straight out of the camera) image:
Here is my image with a global levels adjustment for exposure. This means the exposure adjustment is applied to the entire image. There is no layer mask.
How do you add a layer mask? Layer masks are added to adjustment layers by default but I have them turned off because I like to add masks on my own. It’s easy enough to do. Just click on the add layer mask icon on the bottom of the layers panel.
Here is my image with the global exposure adjustment and a white layer mask. It looks the same as the global adjustment, right? That is because white reveals. So essentially it’s as if it’s not even there.
Here is my image with the global exposure adjustment and a black layer mask. To add a black mask you hold down alt/opt while clicking the add layer mask icon. It makes the image looks the same as the sooc shot, right? That is because black conceals. So essentially it’s as if the adjustment doesn’t even exist.
This is where your brush comes in. On the first example, I have a white mask so I use a black brush to paint over the area I don’t want the exposure adjustment to show up on, which is the sky and the top of the silo. I click on my layer mask to make it active. I can tell it’s active because it has a black frame around it and if I look at the information in the image tab it tells me I am on my layer mask.
Next I grab my brush by clicking on it in the toolbar or by pressing B on my keyboard and I choose a black brush by selecting black as my foreground color from my color picker. I also right click with my mouse to get my brush options and choose a soft round brush so that my painting blends well. I then paint over the sky on my image and the white part of the silo.
I could have gone the other way with the same end result. Here I had a black mask and used a white brush to paint over the area I wanted the exposure adjustment to show up on which is everything but the sky and the top of the silo. So even though we started with a black mask we end up with the same result because white reveals and black conceals.
Don’t forget that you can change the layer opacity and the opacity of your brush to further fine tune your adjustments. You will need to decide if it makes more sense to fill the mask with black from the start of to leave it white, depending on the masking that needs to be done. In this case, it really didn’t matter but if we only wanted to mask out the silo, it would make sense to leave the mask white, grab a black brush and paint over the silo.
The beautiful thing about masking is its non destructive editing. You aren’t deleting any pixels. You are only covering them up. You don’t like what you did? Grab the opposite color brush and paint back over the mask or drag your mask to the trash can and add a new one and start all over again. Think of it like reversible erasing. So go practice and play and have some fun!
Masking out sky and silo: