As noted in this recent blog, OS X 10.4.8 provides a useful new control-scroll zoom feature. I find myself using this quite a bit, whether it’s to read a way-too-tiny font on some Web site, or to make sure I select just the right area of the screen for a screenshot. I particularly like the fine control over the zoom levels; move the scroll wheel a bit, and you get a tiny incremental zoom. This makes it easy to get just the right zoom level.
What I don’t enjoy, however, is the long travel back to the 100 percent view when I’m done with zoom mode. You either have to control-scroll backwards, a step at a time, or hold down Command-Option-minus, assuming you have Zoom enabled in the Universal Access System Preferences panel. Even when using the keyboard shortcut, you have to hold the keys down until the zoom level reaches 100 percent again. I find this annoying—when I’m done zooming, I know I’m done zooming and I just want to get back to the normal view as quickly as possible.
So here’s the trick—visit the Universal Access System Preferences panel, and click the Options button in the Zoom section (make sure Zoom is set to On before you click Options). Now move the slider for the Maximum Zoom setting to anything other than its current leftmost position. Note that the value you pick will not affect the amount of control-scroll zoom you can use; changes made here only affect zooming via the Universal Access keyboard shortcuts. (If you also use the keyboard-based zoom feature and don’t want to lose any zoom capability, move the slider all the way to the right.) Here I’ve set the slider to just over 10x:
Click Done and you’re, well, done. Now zoom in as normal, and when you’re done, press Command-Option-minus just once. The screen will automatically zoom back down to 100-percent resolution without any further key presses. Unfortunately, you’ll have to sit through the animated zoom-out, but it’s still better than having to repeatedly press a keyboard shortcut or scroll the mouse wheel.
If you find the zoom out shortcut cumbersome, you can change that quite easily, too. Open the Keyboard & Mouse System Preferences panel, select the Keyboard Shortcuts tab, and scroll down to the Zoom section. Click the triangle next to Zoom to expand that area, then click the entry in the Shortcut column for Zoom out. Set it to whatever you like, but make sure you pick something not likely to be in use by other applications, as this is a global shortcut. Feel free to change the Zoom in shortcut while you’re here.
If you use this trick, you’ll have one other advantage: two distinct zoom modes. The first, of course, is the control-scroll zoom for fine-grained control. But now, you can also quickly zoom in on the cursor’s location to the maximum value you specified in the slider by pressing Command-Option-equals, which will jump from 100 percent to your chosen zoom level. Command-Option-minus will then smoothly return the zoom level to 100 percent.