Can someone explain layer masks?

The Mack

What? why? when?

lol

I can't find anything that really makes me understand the top three questions...

aj986s

Here's something I found online (Google is your friend.. )

http://photoshoptips.net/2006/07/25/layer-masks/

jfriend

The Mack wrote:

What? why? when?

lol

I can't find anything that really makes me understand the top three questions...

Pretty simple really.

Imagine you have a Photoshop document with two layers. Normally, the top layer takes precedence and only it will show except where the top layer is transparent (then the bottom layer shows through the transparency) or where the top layer is masked or blocked.

So, if you want to block some part of a layer from the image, you can create a layer mask for that layer. Anywhere the layer mask is white, the layer is unaffected. Anywhere the layer mask is black, the bits from that layer are blocked from the final image.

I use masks most often with adjustment layers when I want to confine the effect of the adjustment to only part of the image. So, imagine you have a shot of a person and their face is too dark. You can't make the overall picture lighter because the rest of the shot is properly exposed, just the face is too dark. You can make a curves adjustment layer, bright the image until the face is about right, then fill the mask with black, blocking the entire effect of the curve adjustment, then paint white (with a soft-edged brush) back into the adjustment layer just over the face area. This allows the curve to only effect the facial area.

There are litterally thousands of applications for masks. Generally, you should only use a mask when a global correction (shadow/highlights, selective color, etc...) won't do the job because those are quicker and require less skill to make look good.

jjbong

The Mack wrote:

I can't find anything that really makes me understand the top three questions...

For a deep dive, Katrin Eismann's book is excellent:

http://www.photoshopmasking.com/

pathfinder

Matt Kloskowski's "Layers - the complete guide to Photoshop's most powerful feature" is very good and thorough.

Scott Kelby's "7 Point System for Adobe Photoshop CS3" will get you up an running with layers and masks also.

Learn to use 'Quick Mask' - that is a very fast and easy way to utilize the power of Photoshop.