If you're using Windows and aren't using ZoomIt, you're missing something. We all run into those scenarios where we see an image, but it's not quite as big as we'd like. For those situations, Microsoft gives us ZoomIt. There's not a whole lot to explain here. Download it, run it, and press Ctrl+1 to zoom in. From there, move your mouse around to reposition the view and press up and down to zoom in and out further. There are also options for drawing, typing, and even a timer. These are for presentations and I don't use them much, but I'm sure others find them more useful. If you haven't tried it before, ZoomIt is definitely worth at least trying once. You can even run it from the web to stay up-to-date with the latest release.