IWA-HWG Photoshop Course. Weeks 3 & 4 Review Questions

1. Based on the reading out of the book, what exactly is the function of a transparency mask?
   
   The transparency mask is the information within a layer regarding the transparency and opacity of items within the layer. This information is easiest to see when only the layer of current interest is visible (i.e. it is the only one with an eye on the left hand side in the Layer Palette). When this is the case an item/region that is transparent appears with a gray and white checkerboard pattern, an item/region that is 100% opacity appears solid, and an item/region that has intermediate opacity has the gray-white checkboard showing through somewhat.
   
   
2. What are some of the benefits to using Layer Masks?
   
   At first glance a Layer Mask seems to have the same effect as making a selection from another image or layer and pasting it into its own layer. With this approach one retains only the information within the selection. With a Layer Mask, on the other hand, the entire source image is placed in a layer and the mask makes everything that was not selected transparent. The crucial difference is that the non-selected information remains. One can edit the mask independent of the image and reveal information that was previously masked out (transparent).
   
   
3. Once a mask has been created, how do you edit the mask?
   
   First you select the mask by pressing down the ALt key and clicking on the mask (which is in black and white, the selection being white). This isolates the mask. One can move the white part using the Move Tool. One can paint with white, add white shapes, etc. to expand the mask region. Likewise, one can paint with black, add black shapes, etc. to reduce the selected region. One can also apply a blur filter and make a sharp-edged selection into a feathered selected.
   
   
4. How do you know if a mask is active in the Layer Palette? 
   
   One knows that a particular layer is selected because it is highlighted with blue in the Layer Palette. If that layer has a mask, then either the content or the mask is selected.  To determine which, look for which one has a white outline around it.   
   
   
5. How would you temporarily disable/enable a mask?
   
   If one right clicks on the mask, one can choose to Enable or Disable it.
   
   
6. If you wanted to move either the layer's contents or the mask independently from each other, what would you have to do?
   
   There is a chain icon between the boxes representing the content and the mask in the layers panel indicating that they are linked and will be moved together. However, if one clicks on the chain, the link is broken (chain disappears). Then the image content can be moved independently of the mask or vice versa.
   
   
7. Briefly explain how Layer Masks can help your digital collages and color/brightness corrections
   
   A Layer Mask allows you to apply an adjustment to just the masked area. Suppose for instance that an image has bright regions in it, but some region of interest is in shadow. Brightening the entire image with saturate and flatten the bright regions. However, if the shaded region is selected and turned into a mask, it can be brightened without affecting the rest of the image.
   
   
8. How can the pen tool be useful as a selection tool?
   
   If one chooses any of the variations of the pen tools and have the Paths option selected, then one can draw a closed path and convert it into a selection by going to the Paths Palette (go to Windows/Paths if the Paths palette is not showing) and right clicking on the "Work Path" and choosing Make selection from the context-sensitive menu. A dialog box will appear asking about typical selection options (anti-aliasing and feathering).
   
   
9. How do you add an anchor point to a Path? 
   
   The Add Anchor Point tool is an option under the Pen Tool.  It is the one with a plus sign.  With the Add Anchor Point tool selected, click on a point on the path.  This will add an anchor point and also give one access to the Bezier handles of that points as well as the near Bezier handles of the two adjacent points.
   
   
10. How would you delete an anchor point on a Path?
    
    The Delete Anchor Point tool is another option uinder the Pen Tool.  It is the one with a minus sign.  With the Delete Anchor Point tool selected, the points of a path show up as empty circles. Clicking on an open circle will eliminate that anchor point.  
    
    
11. How do you select an entire path?
    
    One converts a path to a selection by going to the Paths Palette (go to Windows/Paths if the Paths palette is not showing) and right clicking on the "Work Path" and choosing Make selection from the context-sensitive menu. A dialog box will appear asking about typical selection options (anti-aliasing and feathering).
    
    
12. How do you drag points and handles to reshape a path?
    
    The Direct Selection Tool (which is represented by an open arrow icon) is under the Selection Tool which is just above the Pen tools. With the Direct Selection Tool selected, one can click on the path to select it (assuming is was not already selected) and the anchor points show up as empty squares. If you drag one of the empty squares, you are moving the anchor point.  After dragging an anchor point, you will typically have access to its Bezier handles as well as those of the two adjacent points.
    
    
    
13. Explain in your own words what the primary function of a clipping group or layer is. 
    
    One layer can have an effect on the layers beneath it, especially when it is an Adjustment Layer when that is its main purpose but also through Blending Modes for instance.  The effect usually applies to all layers beneath.  However, with the use of a clipping layer, the range of the effect cam be limited to the layers in the group.   
    
    
14. Deke explains how you can improve the appearance of color scans using channels. Briefly explain what some of these techniques are. 
    
    Moving channels: highlight one channel and use the Move Tool to change the position of that color channel with respect to the others.
    
    Focusing of blurring channels: apply focusing techniques (such as Unsharp Mask) or blurring techniques (such as the Gaussain blur filter) to one of the channels.
    
    Mixing channels: Under Layer/New Adjustment Layer/Channel Mixer, one finds the option of taking a channel, say Blue, and making a new Blue channel which is a combination of the old channels (e.g. 80% old blue, 10% old green, 10% old red).
    
    
15. What are some of the benefits to working with mask channels?
    
    Turning a selection into a Mask channel saves it so that it can be edited, copied, etc.
    
    
16. When you save a selection as a mask, where is the mask stored?
    
    When you go to Select/Save Selection on the menu, the dialog box that arises allows you to make a new channel for the mask. If you already have a mask channel, then you can add, subtract or intersect the new selection with the previous one.
    
    
17. How can you edit a mask in a channel once you've saved it?
    
    A channel mask can be edited in at least two ways.
    1. If you make the mask channel the only visible channel it will appear as a white shape on a black background and you can use the Brush Tool or Shape Tool, etc. to add to or subtract from the mask.
    2. If you go to Select/Load Selection and choose the mask channel from the dialog box, then the selection can be edited as a selection. Any changes made here are to the selection and not directly to the channel, but if you want to save them to the channel, you need only go to Select/Save Selection and choose the desired mask channel from the dialog box.