Channels & Masks Video Lesson 8: “Found Masks”

In Lesson 8 from Photoshop CS4 Channels & Masks One-on-One, Deke proves that not all masks require arduous, meticulous hand work and complicated sets of steps. (I know, I can’t believe this is our same Deke, either.) Here, Deke gives your brain (and fingers) a bit of a rest by showing you how to use “found” channel information to create masks with very little effort. This example uses the same image to create both a density and luminance mask by repurposing channel information almost pixel-for-pixel. If you like what you see, there’s more in Lesson 8 of the book, including other found masks like edge masks, depth masks, corrective masks, and color-based masks.

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  • Wicked!

    This is crazy. How do you remember SO much stuff?!

  • Select and roll?

    Hi Deke,
    I am new to Photoshop so I jumped in at CS4 and is still unpacking this amazing tool box. The reason why I mention that is because I don’t know if I have accidentally stumbled upon a very useful shortcut or if it is so obvious that nobody care to mention it.  If I am saying that the sky is blue then so be it and you can ignore and even delete this post.
    This is what happened:  While working on an overlay I selected ‘multiply’ and forgot to press the esc key, that you so patiently remind us to do,  when I wanted to change the opacity. (I work in a PC with windows XP) Then, with the multiply selected, I accidentally scrolled with the wheel on my mouse and everything went ‘kaflooey’, to quote a famous Photoshop author and video teacher. Or did it?  I noticed that the next overlay was selected and if I continue rolling the mouse’s wheel that I could scroll up and down watching the effects of the overlays while looking at the screen. (No shortcuts to remember)
    The same technique (scrolling with the wheel) also works on values such as brightness, contrast and even in levels where the shift key increase the increments of 10.  It is a matter of ‘select and roll’ while watching the picture where the action is!  Obviously I did not have the time or expertise to check it everywhere. Incidentally, it isn’t as if I do not appreciate the ‘shift up and down arrow’ to change values and I also use that a lot.

    Is this a happy accident or can I expect ‘select and roll up to 50’ in future tutorials?

  • Speaking of Masks… New Illustrator Clipping Mask Behaviors

    Illustrator CS4 seems to have introduced some quirky (but welcome Freehand-like) new behaviors with Object… Clipping Mask… Make.

    P’haps these are properly called “Object Clipping Masks” (for example, you must now enter isolation mode before you can select pieces of a masked object that lie outside the mask similar to “paste inside”)

    that seem to differ from the traditional ol’ “Layer Clipping Masks”. (The mask must be top object in a layer and it masks all the stuff in the layer beneath.)

    My question is: How else do these two clipping mask types differ and why you would choose one type over another (advantages, disadvantages)? Or, to put it more simply, why do these two types of clipping masks both exist?

    If your answer is, it’s covered in my coming Illustrator videos, wait and you will be enlightened… that’s cool. I appreciate your feedback and Mordy’s as well if he is lurking around grin

    hijackin’ the thread with an Illustrator question,


    Thomas Benner

    The Art Institute of Austin

  • While that works only on Windows

    It’s a fantastic tip! I’m so used to being irritated with “sticky” options under Windows that I sometimes fail to acknowledge the (extremely few) advantages.

    But you know what, I’ll give it a nod in the videos I’ll be recording this very week at “Select and roll,” I love the phrase even.

    Mind if I steal? It’s theft for the greater good, after all.

  • I don’t mind at all. The

    I don’t mind at all. The ‘feature’ was there all the time and I merely stumbled on it by accident. It isn’t theft if it did not belong to me in the first place. What about “select and wheel?” Nah.
    By the way, I have Photoshop CS4 one-on-one on order (started with Channels & Masks) and it will be some time before I use my free pass to to see the videos.  I live in Africa and all your books are not in the bookshops, yet.  (Think: I wonder if the tip isn’t worth a month’s subscription?)

  • Man, this stuff is so

    Man, this stuff is so good… So I just dished out and ordered the book, can’t wait!

    You have an uncany ability for making people (me?) understand what’s behind the technique that’s just, well, great.

    Thank you for your efforts. A little bit of my money is on it’s way to you…

  • Mask Types

    Illustrator actually has three types of masks—Clipping Masks (CM), Layer Clipping Masks (LCM), and Opacity Masks (OM). I actually just finished recording my latest title at (Illustrator CS4 Beyond the Basics), where I go into detail on all three types of masks. It should be a few weeks though before the title goes live.

    In regard to CM vs. LCM, there are pros and cons to both. Mainly, the new CS4 functionality where objects that fall outside the mask are not able to be selected with the Selection tool applies only to CMs. LCMs have the ability to preserve layer structure. This blog post shows how to preserve layer structure within an LCM

    Mordy Golding

  • The Return of the Masked Avenger

    Who was that masked man?.... None other than Mordy Golding. :•)

    Thanks for chiming in Mordy. Your division of masks actually makes sense.  I’m eagerly awaiting the new videos as I expect you will carefully dissect these masking features and elaborate on the pro’s and con’s. I have always appreciated what you do on and your Real World Illustrator web site and love telling my Illustrator classes about them.

    I had already studied your blog post on LCM (another acronym!) where you mask the city skyline and “maintain layer integrity” and think it is quite good.

    BTW, I have previously always warned my students to NOT do their web site design in Illustrator. Your Illustrator for the Web class is slowly changing my mind on that grin



    Thomas Benner

    The Art Institute of Austin

    p.s. I am grateful you answered my question as you will always be “Mr. Illustrator” to me.

  • ‘Blend If’ and found Luminosity Mask

    I’ve been finding the ‘blend if’ function handy with found luminosity masks.

    If I want to reduce shadow noise in a digital image I de-noise one copy of an image, and leave the other version alone on a separate layer. Then with ‘blend if’ I can push the de-noised darks from the lower layer up through the untouched upper layer. The sliders make the process previewable in real time.

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