Sony DCR-TRV310

We originally purchased the Sony DCR-TRV310 for home video of family events. On a lark, I decided to point it into the eyepiece on night and was pleasantly surprised that I got reasonable images. It just so happened that I picked the moon as a target and it was only slight after the new moon. This was fortunate in that the entrance pupil of the camera is not well matched to the exit pupil of the 25 mm Plossl eyepiece I was using (25 mm with an f/6 scope gives an exit pupil of 4.2 mm, rather large for the video camera).

When the full image cannot enter the camera, you end up with a shadow from the secondary in your images. But, because I was imaging a very thin crescent moon, the shadow from the secondary fell in the dark part of the moon so I couldn't tell. And, because I couldn't tell, I went on to try imaging Jupiter and Saturn.

Sorry, I don't have any technical details on the Sony DCR-TRV310, but once I do, I'll try to post them here.

Using the DCR-TRV310

For the planets, the DCR-TRV310 can be used in the normal 29.97 frames-per-second mode. For deep-sky objects the camera's "candle-light" mode is preferable. In this mode, the camera increases the exposure time by approximately a factor of 8 to produce 1/4-second exposures. Output continues at the 29.97 fps rate, but each set of 8 frames is identical.

The DCR-TRV310 has three output methods, composite video, S-Video, and FireWire. The latter is preferred as it is completely digital and what was used. Capturing over the digital FireWire connection makes it easy to get rid of duplicate frames when using the candle-light camera setting; each set of 8 frames is completely identical and any tool which will allow you to compare files will tell you which ones are unique.

Because the DCR-TRV310 is a standalone camera, you don't need any computer at the site to do your video capture; just a supply of digital 8-mm tapes and your telescope.