View Full Version : Still have a hard time understand masks


kneff
06-16-2007, 02:14 AM
I have gobs of books on Photoshop CS2. I retouch photos, and I see alot of people use masks, but these have got me so confused. I've read the books, I've watch the tutorials, maybe I just need to hear it from someone in simple terms. This is probably a stupid question for alot of you because I know masks are very common, but its just not bumping my brain. Any help would be wonderful!!
Thanks so much.

Graphics23
06-16-2007, 07:15 AM
In simple terms, a mask is a grayscale image and can be edited in exactly that same ways one would edit any grayscale image. It has many uses, such as hiding parts of a layer or controlling where and how a filter is applied.

Let's do a little exercise.

Every adjustment layer comes with its own Layer Mask which is represented in the Layers Palette by a second icon on the layer in question.

Open any image and create a Curves Adjustment Layer. Don't make any adjustment, just hit OK to dismiss the dialog box.

You should see two icons on this layer. Double-clicking the left icon opens the Curves dialog again, single-clicking the right one selects its layer mask.

Notice that when you single-click the layer mask icon it shows an outline around the icon. This indicates that you can edit the mask. Right now the layer mask icon should be white, but we're going to change that.

Now set the layer's Blend Mode to Multiply. You should notice the entire image become darker. But suppose you want one part of the image to remain unchanged. This is where the layer mask comes in.

Click on the Layer Mask Icon. Hit the "B" key to select your Brush tool. Hit the "D" key to get your default colors. Hit "X" to make your foreground color black. Now paint anywhere on your image. You'll notice two things, the area being painted reveals the original pixels and the layer mask icon has got some black in it.

Now hit "G" to select the Gradient Tool. Make sure you're using the Foreground to Background gradient and drag your mouse across the middle of the image. Now you should see half the image is dark and fades back to the original image. You'll also notice the Layer Mask Icon has a gradient that fades from black to white.

This is a very important point regarding masks; white reveals, black conceals! Say it again; white reveals, black conceals. Memorize it. This means that areas on the mask which are black hide what's on the layer, "masking" the layer's content. Areas on the mask which are white allow the content to remain visible.

Play with this for a while. The only way you'll become familiar with masks is to use them. There's no short cut around this. All the books and videos in the world won't help if you don't experiment.

Good luck,

Michael

smak
06-16-2007, 07:35 AM
You decide to put a mask on a layer. A mask is connected to that layer. A mask controls how much of that layer is visible and how much of that layer is not visible (like erased). If you understand the eraser tool, then:
An analogy could be: Black erases that layer. White does not erase that layer.
Where you paint black, the layer underneath shows through.

des151
06-16-2007, 07:37 AM
Michael,
Shiver me timbers, nice post matey.
Ray

Dena
06-16-2007, 07:58 AM
Masks have been tough for me too.

I recently bought Katrin Eismann's "Restoration and Retouching" book which helped me grasp it much better. And in fact, I now find using masks so helpful, that I am starting on her "Masking and Composing" book. I love the way she writes her books... not only are they very easy to understand but somehow she just makes you really WANT to learn. :)

You can read more about her masking book here: http://www.photoshopmasking.com/

Dena...

Swampy
06-16-2007, 12:24 PM
The rule of masking....White reveals, Black Conceals

So duplicate a layer and run something real funky like a stain glass texture on the duplicate. Add a mask to this stain glass layer (click on the square icon with a hole in it at the bottom of the layer's palette)

The mask defaults to white and reveals the stained glass effect ON THAT LAYER. But if you grab a brush with black as the foreground color and paint black on the mask the black conceals the stained glass and passes visibility of that area through to the layer below (no stained glass).

Repeat after me...

"White REVEALS the effect (texture, adjustment, art filter) of the image on this layer EXCEPT where I paint with black."

If you remember that one sentence then the opposite is true.

"Black CONCEALS the effect (texture, adjustment, art filter) of the image on this layer EXCEPT where I paint with white."

Doug Nelson
06-16-2007, 12:33 PM
My own personal mnemonic is "black blocks" (easier for me to remember).

smak
06-16-2007, 01:22 PM
I say this only to encourage you, "there's nothing hard about masks." Using them is not as difficult as it may seem. "There's nothing.....

cspringer
06-17-2007, 09:48 PM
Just do it...there isn't anything to them.

Open a picture with a subject (i.e., a flower).
Add a Hue/Saturation adjustment layer (they come with a mask).
Desaturate.
Click the mask and paint over subject with a black brush to bring back the color from the layer below.
That's basically all there is to a mask.

2.
Open the same picture and add a hue/sat. adjustment layer and desaturate the image.
Click the mask and Ctrl+I to invert it to black.
Grab a White brush and paint over areas you want desaturated.

Volvo
06-24-2007, 01:43 PM
Hokeydokes my turn :)...Another good way is to have a look at your Photo and see what editing you wish to make??,for instance say you had a flower with yellow petals and green folliage..Now the folliage is green enoughbut the petals aint yellow enough:)..
You can open a hue sat adjustment layer and really bring up the yellows to where you wish, BUT this change may go right through the whole picture and would take sooooo long undoing the change with your normal white mask attatched to your adjustment layer as previousely explained in other threads, so what we can do here is.
Left click in your mask..
Alt backspace and your mask should now go completely black..
(This masks out all the change you made in your hue sat adjustment layer)
Select white as your foreground colour and with the appropriate sized brush, brushing only in the flower petal area and a low opacity if you wish you can slowly bring back enoughof the colour change to the flower only that you wish:)..
Or, leave the opacity as is and brush in the whole colour change to the petals..
By lowering the opacity and slowly brushing in your change you get the change to suit ..
I find i use this method much more even if i do sections at a time with one Photo to bring out various changes to it..
Cheers and hope i made sence of it all lol..

smak
06-24-2007, 05:14 PM
>>>>>>>>> Just do it...there isn't anything to them.

I agree with this. Don't overthink or analyze, just put one on a layer and paint black or white on the mask.