A camera with a 10x zoom (and 32x digital x optical zoom) takes pictures differently from cameras with 3x zoom (pretty much standard on all digital cameras today) and no zoom (our old film-based SLRs with their "standard" but useless 50mm lens).
You're proud of your S1iS having 10x zoom. But there's a problem. Many photos taken with 10x zoom look pretty much as if the photo was taken at 3x or 0x zoom. Here's an example, at left above.
Take Closeups of the Moon
1. Place your S1iS on a tripod, and use the self-timer (set it to 2 seconds, so you don't have to wait 10 seconds) to trip the shutter. Using the self-timer prevents the camera from shaking when you press the shutter button.
2. The exposure is trickier, because the camera's exposure meter is fooled by the bright light of reflected sunlight against the black backdrop of outer space. Below is the moon photographed by the S1iS in automatic exposure mode. Not pretty
I changed the camera to Manual, and set the aperture to its widest opening, f3.1 (the maximum at 10x zoom). The widest lens opening gives you the clearest pictures; the smallest lens opening gives you more depth of field (range in focus) at the expense of less clear photos.
3. I tried different shutter speeds, and found that 1/125 was pretty good.
5. The camera had difficulty focusing (a problem common with 10x zooms), so I changed to Manual focus, and set the focus distance to infinity.