Adobe Photoshop 7.0 for Photographers- P7

Adobe Photoshop 7.0 for Photographers- P7: In 1996, a group of self-proclaimed ‘digital’ photographers met together at IanMcKinnell’s studio in Holborn, London, to discuss the formation of a DigitalImaging Group. At first, this was a small gathering of professional photographers.The one thing we all had in common was a shared interest in using computers andtheir potential as a photographic medium of the future.
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Adobe Photoshop 7.0 for Photographers- P7 Adobe Photoshop 7.0 for Photographers Chapter Eleven Montage Techniques C onfusion often arises when trying to understand the relationship between alpha channels, masks, Quick mask mode and selections. Let me help ease the learning curve by saying they are interrelated and essentially all part of the same thing. That is to say, a selection can be viewed as a Quick mask or saved as an alpha channel (also referred to as a mask channel). An alpha channel can be con- verted to make a selection, which in turn can be viewed back in Quick mask mode. Also discussed later in this chapter is the use of image layer masks and vector masks and how to draw paths with the pen tool and convert these to selections. Selections and channels So when you read somewhere about masks, mask channels, image layer mask channels, alpha channels, Quick masks and saved selections, the writer is basically describing the same thing: either an active, semipermanent or permanently saved selection. We will begin with defining a selection. There are several tools you can use to do this – the marquee, lasso, magic wand and Select > Color Range. The marquee comes in four flavors: rectangular, oval, single pixel horizontal row and vertical column. The lasso has three modes – one for freehand, another for polygon (point by point) drawing and a magnetic lasso tool. When you use a selection tool to define an area within an image (see Figure 11.1), you will notice that a selection is defined by a border of marching ants. Selections are only temporary. If you make a selection and accidentally click outside the selected area with the selection tool, it will disappear – although you can restore the selection with Edit > Undo (Command/ Ctrl-Z). 280Please purchase PDF Split-Merge on www.verypdf.com to remove this watermark. Montage techniques During a typical Photoshop session, I will draw basic selections to define areas of the image where I want to carry out image adjustments and afterwards deselect them. If you end up spending any length of time preparing a selection then you will usually want to save the selection as an alpha channel (also referred to as a mask channel). To do this, choose Save Selection from the Select menu. The dialog box will ask if you want to save as a new selection. Doing so creates a brand new alpha channel. If you check the Channels palette, you will notice the selection appears there labeled as an alpha channel (#4 in RGB mode, #5 if in CMYK mode). To reactivate this saved selection, choose ‘Load Selection’ from the Select menu and select the appropriate channel number from the submenu, or Command/Ctrl-click the alpha channel in the Channels palette. You don’t have to use the selection tools at all. You can also create a new alpha channel by clicking on the Make New Channel button at the bottom of the Channels palette and fill the empty new channel with a gradient or paint in the alpha channel with a painting tool using the default white or black colors. This new channel can then be converted into a selection. In between masks and selections we have what is known as a Quick mask. To see how a selection looks as a mask, switch to Quick mask mode (click on the right-hand icon third up from the bottom in the Tools palette). Now you see the selection areas as a transparent colored overlay mask. If the mask color is too similar to the subject image, double-click the Quick mask icon, click on the Color box in the opened dialog and choose a different color with the Color Picker. In Quick mask mode (or when working directly on the alpha channel) you can use any combination of Photoshop paint tools, Image adjust commands or filters to modify the alpha channel content. To revert from a Quick mask to a selection, click the selection icon in the Tools palette (a quick tip is to press ‘Q’ to toggle between the two modes). To reload a selection from the saved mask channel, go Select > Load Selection. Command/Ctrl-clicking a channel is the other shortcut for loading selection and by extension, combining Option/Alt+Command/Ctrl-channel # (where # equals the channel number) does the same thing. Alternatively you can also drag the channel icon down to the Make Selection button in the Chan ...