Use Your Favorite Navigation Shortcuts In Camera Raw
If you want to change the size of your preview window in Camera Raw, you can use most of the same keyboard shortcuts you already use in Photoshop. For example, to zoom in press Command–+ (Plus Sign) (PC: Control–+), and to zoom out press Command–- (Minus Sign) (PC: Control–-). To jump to Fit on Screen view, double-click on the Hand tool. To jump to 100% size, double-click on the Zoom tool. To temporarily get the Hand tool, press-and-hold the Spacebar, then click-and-drag within the preview area.