Dave Wallace's Adventures in Astronomy

02/14/2004 2230 UTC

Finally! The weather has warmed up enough to try an experiment or two with the LPI. I set up at 5:30 PM local time in my driveway and aimed the telescope at Saturn, which at that time was just a little brighter than the evening sky. After a bit of struggling with the alignment, I had the telescope tracking the planet and had it centered in the field of my 15mm eyepiece. I swapped in the Barlow and re-focused. Swapping the optics disturbed the positioning, so I had to re-center. (The mount's a bit "soft"; it's easy to move the scope a few tens of arc-seconds if I get too rough.)

I booted the laptop, attached the LPI and launched the Meade Autostar Suite. Since I wasn't trying to control the telescope from the software, I just went straight into the image capture application. Out with the optics and in with the LPI camera! Adjust the video parameters... Aha! A picture. Hmm... focus isn't perfect and the image is moving around a bit. Tweaked the focus as best I could. Re-centered the image, but it still was wandering around. Oh well, let's see how good this capture software is...

All in all, over the next hour, I took eleven pictures of Saturn made from between five and fifty frames. (Each frame was a 3/8th second exposure.) None of these pictures are worth inflicting on the public. :) But I did determine that the resolution of the LPI when attached to the ETX-90 OTA is just about one arc-second per pixel. And I really must make improvements to the home-brew mount if I'm going to do this sort of photography: the image capture software doesn't like it when the target wanders all over the field.

My best effort was a picture about 45 by 25 pixels showing a circular blob with "wings". Which would be very discouraging except that Galeleio's drawing of Saturn looked pretty much the same. At least my photo doesn't have the chromatic abberation he had to put up with -- the colors look fairly reasonable. So I can probably improve everything except the resolution by getting the focus more exact and making mechanical improvements to the mount. It's a start, anyway.