High-resolution images take up a lot of memory so use fast, large-capacity storage cards (4 to 8 gigabytes, or more) to avoid running out of memory at a critical time.
8. Shoot the transit in hydrogen-alpha:Specialized hydrogen-alpha telescopes, such as the Coronado PST and SolarMax II series from Meade Instruments, provide stunning details on the sun, which make for a dramatic backdrop to Venus' disk.
Unlike ordinary, unfiltered light from the sun, also known as "white light," H-alpha is the red light emitted by hydrogen atoms in the sun's atmosphere, called the chromosphere, at a wavelength of 656.3 nanometers. If there are large solar prominences along the edges of the sun, it might be possible to glimpse Venus against a prominence right before the planet's disk enters, and right after it leaves, the sun's disk.
9. Shoot with video: As with digital cameras, you'll need a proper solar filter over the camcorder's lens. Many camcorders have zoom lenses with up to 40x or more optical magnification. To videotape the transit, simply mount the solar-filtered camcorder on a tripod, aim it at the sun and zoom in to its highest power. Use the camcorder's manual settings, if available, to prevent the sun's image from getting overexposed. Take short clips every five minutes or so to create a short time-lapse movie of the Venus transit.