Lorace,
There are many reasons and I’ll let others chime in, but one is to give the appearance that one object is behind another. Example, you have a picture of a person and a picture of a tree, and want to make it look like the person is peeking out from behind the tree. A mask in the shape of the tree covering half the person would accomplish this.
The advantage of using a mask is that you don’t erase any of the person, and can reposition them later.
Rich
Lorace,
I use PSE to make minor adjustments to photos, no piecing together parts of different pictures. But I use masks all the time to make adjustments to different parts of a picture. For example, a properly adjusted sky with a dark foreground; mask out the sky, and the adjustments will apply only to the foreground.
Both good reasons to use a mask.
I also use a mask when making a particularly difficult selection.
I make a lose selection around the subject, then make a new layer and call it "mask" and with the new layer active, I fill the selection with white, then I inverse the selection and fill the inverse with black. Now I lower the opacity of the white/black layer so I can see the actual image through it.
Now I paint with wither white or black so the white exactly covers what I want to select. When I’m satisfied that the subject is all white on the mask layer, I use the magic wand to select the white and Voila!! I have a selection which I then save.
You can now delete the mask layer if you want and use the saved selection to pick out your subject.
Hope this helps, Margaret
Margaret,
You could also just add a layer mask and not have the difficulty seeing your subject ‘under’ your new layer. Using the rubylith color scheme you paint with black to cover up what you want to hide (though it shows as as semi-transparent red which you can see through). The part you wish to keep is always portrayed exactly as the in the ‘original’. Just a thought.
Nancy
I want to thank each of you very, very much for your wonderful suggestions. It’s so nice of you to take the time and effort to help those of us to whom all this is so new.
You may clap your hands for me tonite, as I had my first real, real breakthrough with maskes. I had been working with Jay Arraich’s online tips about Layer Masks. And I think I worked on this for three nights and never got anywhere.
Then, tonight, I realized when I was blacking out something, I should click on the mask itself, rather than on the picture. And I watched the pumpkin disappear right before my eyes and the background came through and his hat was floating on the background picture. Eureka! I about fell through the floor.
Just a little thing, but what a thrill it was to me!
So, I’ve printed out your notes and will utilize them in my practice sessions.
What a great, helpful group. Thanks.
Lorace
Nancy, you’re confusing me. What do you mean by "layer mask" ?
If you mean create an adjustment layer and then use the "mask" box – I find my method works better for me because the white/black shows exactly what I’ve painted over.
In Photoshop 6, there is a layer mask that I use all the time, but in PSE, the best advice I could find was to fake it the way I’m doing.
Please enlighten me,
Margaret
Margaret,
Whatever works best for you is the way to go. I was just mentioning that it is possible to use a true layer mask, such as you routinely use in PS6 (not using the mask from an adjustment layer to which you input nothing).
Free third party add-ons give this functionality (and many other useful features) to PSE, both versions.
<
http://share.studio.adobe.com/axQuickSearchSubmit.asp?txt=to ols&allprods=2&submit1.x=30&submit1.y=10>
"This package comes with some actions pre-installed and several free tools, including:
true layer masks
quick mask
Selective Color adjustment layers
Channel Mixer adjustment layers
Action Playback speed control"
If you happen to use PSE version 1, as I do, this will also give you a layer mask (for Windows)
Ctrl/A > Ctrl/C > Ctrl/shift/V > Ctrl/J
and then link the thumbnails
Nancy
I thought you meant that it was built in to PSE
Margaret
Margaret,
Well it is now built into my copy ;), through the add-ons, though I often just use the keyboard shortcuts to create one.
Nancy
Hey, all you smarties on here! Now that I can make a mask or two with your help and Jay Arraich’s, I do have one further question.
Please don’t get discouraged with me.
But how do you ascertain what type of mask to make?
I make one a certain way (using the effects/frame choice w/alt) and another using the Ctrl-a Ctrl-C – etc and paste into, but am wondering how you know? The gradient one throws me for a loop.
Will I ever learn?
Thanks, again. I’m afraid I’m trying your patience. Just tell me if I am.
Lorace
Lorace,
I am not totally comprehending your question but I’ll just throw out a few things.
Making a mask is making a selection. A mask hides some of the image or layer and reveals that portion which you want to change. When a mask is involved any and all changes will only be applied to that portion of the image which is revealed by the mask. One can change the color of that section, blur it, add a gradient to it or anything else you can do to an image. An advantage of using a mask is the flexibility it offers. One can easily expand/decrease the perimeter of the selected area at any time, you are leaving your original pixels untouched and you can also apply your correction to the selection by degrees. Instead of having the revealed section pure white (100% transparent), painting on all or part of the white area of the mask with black, at say 50% opacity, will allow your correction to be applied in that zone at 50% strength.
If you want to change only part of an image, masking is a good way to separate out the area(s) that you want the change applied to. Hope this helps.
edit: Though you may want to add a mask that affects the whole image. Example: If I wanted to add a faint rainbowlike gradient from red to yellow to my whole image, (on a new layer above the image)I would add the gradient and link it to a mask which was all white (the whole image receives the red to yellow). If later I decide I would rather have the gradient go from yellow to red, this is easily done because I have not directly applied the gradient to my image thereby permanently changing the colors. If I decide not to have the gradient at all, I’d just delete the layer.
Thanks, Nancy.
That did help.
I guess my problem has been in not knowing how to achieve a mask in the first place. I’ve read so many different ways to do it, and on my Layer tab, I don’t have "Mask" like so many articles tell you to choose. (I guess this is a Photoshop feature.)
I’ll get there, and thanks, again.
Lorace
After I learned to use a mask for making a selection, that’s all I used it for and then I started to discover other uses like Nancy described above, Masks rule!!
I have Photoshop 6 as well and that’s where I learned to use the layer mask button and missed it when I made the switch to PSE, but as Nancy pointed out there are third party add-ons for accomplishing the same thing and my method works well for me.
As long as you always work on a copy, not the original, you can experiment to your heart’s content.
Have fun, Margaret
