• Double click on a thumbnail to switch to a Full Screen view of the image
• In Full Screen, move your mouse pointer to the bottom border of the screen where a control bar will pop up to provide fast access to major program functions. (Note: Moving your mouse pointer onto this control bar will enable the mouse wheel to be used for zooming in/out on the image)In Full Screen, move your mouse pointer to the right border of the screen where an image properties window with EXIF metadata will pop up
• In Full Screen, move your mouse pointer to the top border of the screen where a thumbnail browser window will pop up to provide fast access to other images in the same folder and other program commands
• In Full Screen, move your mouse pointer to the left border of the screen where a panel will pop up to provide fast access to file and image editing functions
• In Full Screen, move your mouse pointer to the right-bottom corner of the screen where the Windows Taskbar will pop up to provide fast switching to any other programs being run (Windows XP only)
• When the mouse cursor becomes a magnifier shape, it means the displayed image has been formatted to fit within the current available window or screen area. Now you can press and hold the left mouse button and the image will be viewed in a magnifier. With the left mouse button being held down, moving the mouse around will move the magnifier across the image. The Magnifier zoom ratio and Magnifier size (See Magnifier tab in the Settings) determine the magnification level of the image within the magnifier and the size of the magnifier area
• When the mouse cursor becomes a hand shape, it means the displayed image is larger than the current available window or screen area. Now you can press and hold the left mouse button and move the mouse around to pan/scroll the image within the current window or screen area
• When Normal (Pan) mode is selected, pressing and holding the Ctrl key will change the mouse cursor to a cross shape. Now you can use the mouse to SELECT and ZOOM (select a rectangular area of the image by using the left mouse button to click and drag, then release the button to zoom in on that area of the image)
• When Rectangle, Circle or Freehand select mode is selected, pressing and holding the Ctrl key will change the mouse cursor to a cross shape. Now you can use the mouse to define a selection area. By clicking your right mouse button with the mouse cursor within the selection area, a pop up menu will appear that allows you to zoom, copy, cut, crop or delete the selected area or to even save the selection into a file
• Scrolling your mouse wheel will display the next or previous image
• Holding the Ctrl key, the mouse cursor will become a cross shape – scroll your mouse wheel to zoom in or zoom out on the image
• Holding the Shift key, the mouse cursor will become a circle shape – click the left mouse button to zoom in or the right mouse button to zoom out on the image
• Press Spacebar, Right arrow or PgDn key to go to the next image
• Press Backspace, Left arrow or PgUp key to go to the previous image
• When the displayed image is larger than the current available window or screen area, press Arrow (Up, Down, Left, Right) keys to pan/scroll the image within the current window or screen area
• Press Home key to go to the first image
• Press End key to go to the last image
• Press 1,2,3,… or 0 key to zoom the image to 100%, 200%, 300%,…1000%
• Press A or / key to display the image in actual size
• Press B or * key to display the image in best fit within the current window or screen area
• Press + key to zoom in on the image
• Press - key to zoom out on the image
• Press C key to start the copy to folder function on the current image file
• Press M key to start the move to folder function on the current image file
• Press D key to pop up the Draw Board window to add text, lines, rectangles, ellipses, highlighted areas and watermark(s) to the image
• Press E key to edit the image with the first External Program (user defined)
• Press I key to display a window with the image properties including EXIF and Histogram. Press I key again to hide this window
• Press S key to pop up the Slideshow Options window to configure a slideshow
• Press T key to pop up the JPEG Comment window to edit the image description/comment (for JPEG images only)
• Press L or < key to perform a rotate left
• Press R or > key to perform a rotate right
• Press H key to perform a flip horizontally
• Press V key to perform a flip vertically
• Press W key to open Windows Explorer at the current directory
• Press X key to pop up the Crop Board window to perform cropping on the image
• Press Ctrl+R key combination to pop up the Resize/Resample window to resize the image
• Press Ctrl+H key combination to pop up the Histogram window for the image
• Press Ctrl+Z key combination to undo the last change made to the image (multi-level undo)
• Press Ctrl+Y key combination to redo the last change made to the image (multi-level redo)
• Press Enter or F key to switch between Full Screen/Browser View or Full Screen/Windowed View
• Press mouse wheel button to switch between Full Screen and Browser View
• Press Esc key to exit from Full Screen or to exit the program when in Browser or Windowed View
• To sort images by Filename, Type, Dimension, Size or Date in Browser View, change Browser Style to Report View and left click on the appropriate column header

ACDSee is one of the most popular commercial image viewers (and more) on the market. You can squeeze more out of it via these keyboard shortcuts.