by Richard Crisp
i used the 18" f/12.6 classical cassegrain in pursuit of the Crab nebula last night. I decided to try some non-emission line imaging for a change.
I ended up shooting five shots of 20 minutes through a clear filter. I used the ST10XME and AO& with an Astro-Physics 0.67X ccd focal reducer.
This is the first time I have used that particular imaging system on the big cass.
Seeing was tricking me last night. I'd stand up and look naked eye at the sky and things looked clear and reasonably steady. But when it came time to focus and track, the seeing was clearly not so steady.
I never saw any stars tighter than 3 arc-sec and most were closer to four.
I ended up calling it quits about midnight because the seeing just wasn't giving me what I needed to take advantage of the capabilities of the big cass.
I will fiddle with my data some today to see if some of the deconvolution sharpening tools will help it.
On the upside the scope is working well, the st10xme used self guided with the AO7 and focal reducer is working well too. And the size of the Crab on my sensor is great. With some good seeing this will look really nice.
Posted on sf-bay-tac Dec 18, 2004 09:44:05 PT
Converted by report.pm 1.2 Jan 24, 2005 19:17:27 PT