Everyone knows you can use the Command + or Command – keys to zoom in and out on an image in Photoshop – or, at least I HOPE you know that. But sometimes that can be tedius to hit the key combo several times back and forth to zoom in and out when making adjustments. There is an easier way. If you want to fill your screen with the image at the largest size that will fit, you can double-click the little Hand Grabber tool. If you’re zoomed way in on an image and want to quickly go back to 100%, you can double-click the Magnifying Glass tool.