Focusing

As with film astrophotography, you need to obtain perfect focus, since any errors will show up prominently. You can begin by focusing the telescope visually using the eyepiece (if you use prescription glasses, wear them) and setting the camera lens to infinity. If the camera doesn’t have a manual override, just use its autofocus mode. The built-in LCD screen can be used for centering and focusing, but some people find it a bit too small and coarse to judge the focus precisely.

If your camera has a video output, you can connect it to a larger monitor (say a 13-inch portable TV) to help you adjust the fine focus while watching the TV screen. This real-time video display is also useful when good seeing is intermittent – you can use the video to judge the best time to take the images.

Imaging the Sun through the telescope requires a proper, safe solar filter (click here for a list of filter vendors). Be sure to cover the front of the camera’s viewfinder. Focusing with the LCD screen in bright daylight can be tricky, so shade the screen or use an external, shaded TV monitor. (Some people attach a loupe to the LCD screen with rubber bands or Velcro for added accuracy when focusing and to assist in viewing the screen in bright daylight.)

As with film astrophotography, a good-quality finder is helpful for aiming the telescope. A larger, higher-power guidescope, if precisely aligned with the main scope, can help in getting small targets such as planets into the camera's view.