I don’t have a definitive list but if you do see a blank image instead of what you were expecting, this could be why. Apparently, some Mac apps don’t allow screenshots to be taken of them. I have experienced this on a few occasions and I couldn’t work it out for the longest time. If you find your screenshot appears blank and not what you are expecting, you’re not alone.
Drag to include the menu and a little window context.Select Command + Shift 4 and the cursor changes to a crosshair.Getting a good screenshot of a menu is an essential part of creating tutorials as it accurately describes what you are asking the reader to do. png file on your desktop the same as the other methods here.
Click the mouse button or tap the trackpad to make the capture.Move the camera over the window you want to capture.Select Command + Shift 4 and hit Space.You can use the above method to drag and select an area of the screen that includes the window but there is also a command that captures just the window. Often it is useful to just capture an active window or dialog within OS X to make a point.