February 29th, 2008 | Published in Google Photos (Picasa)
If you spend a lot of time in Picasa, here's a keyboard shortcut that may come in handy: When you're in Library View, move your mouse cursor over any picture thumbnail, hold down the 'ctrl' key, and then press 'alt.' You'll instantly get a full-screen view of that picture.
Obviously, this wee bit of trickery isn't meant to replace a full-screen slideshow -- the moment you take your finger off the 'alt' key, you'll be returned to the regular Library View. But it's a great way to quickly jump in and out of full-screen zoom so you can preview pictures in detail. This trick also works on the current photo when you're in the Edit Room.
If you're looking to quickly compare a few adjacent thumbnails with the benefit of a full-screen view, simply scroll the mouse wheel when using the ctrl-alt key combo. (This is especially handy if you've just imported a clump of similar photos and want to quickly decide which to keep.)