When shooting the moon or other distant objects it’s sometimes better to use a camera with a cropped frame sensor because the crop gives you a slight magnification factor. In the case of my T2i, I get 1.6 X whatever the lens gives me, but this is balanced by a reduced angle of view. So when I put on my 70-300mm lens for a moon shot, I get an effective 480 mm lens, and the reduced angle still leaves enough degrees sky in frame to easily capture the moon, even with full zoom.
The other things to do or set are:
- Weight down your tripod
- Take off image stabilization if your lens is equipped
- Set to full manual everything and dial in these settings:
- ISO 100
- F-11 or F-13 aperture
- 1/125th shutter speed
- Remote shutter release
- Get the moon centered
- Lock all tripod adjustments
- Lock up your mirror
- Turn off auto focus after achieving focus
- Use the live view magnification feature to fine tweak the focus
- Put a small sandbag atop the lens and camera to reduce shake from the shutter
Then snap away with your remote release.