Fremont Peak

by Richard Crisp

Saturday night 14 May was a decent night on the peak. I set up for widefield imaging by the workshop/restrooms area and after worrying about some thin high clouds that disappeared around sunset, I managed to shoot two full color images over the night using my 150mm Pentax medium format lens attached to my ST10XME with focuser and filter wheel. That setup gives me a very large FOV, approximately 23 square degrees.

it was wet up there but very light wind. by morning my car was soaked. fortunately my dewshield was adequate to prevent dewing. I am not sure why but it worked fortunately.

I was making first light tests of my mounting box that I posted a couple of days ago. This gives me full camera angle adjustment and a separate guide system with no differential flexure.

I also was making first light tests of my new 7 slot filter wheel. This is a big productivity benefit for me because i can keep my LRGB filter set in the same wheel as my three common emission line filters ([SII], Ha, [OIII]). In short, I can image galaxies and nebulae in the same night.

here's the final setup I used for the imaging:

http://www.narrowbandimaging.com/mounting_system_cla_page.htm

For targets I began the evening with a widefield shot of the M86 area. I must have hundreds of galaxies in this FOV:

http://www.narrowbandimaging.com/M86_widefield_st10_pentax150mm_page.htm

After finishing this comparatively short 1.5 hour exposure (30 minutes x 3 filters), I moved over to M16. I discovered that M16, M17 and a little imaged nebula NGC6604 would all fit into the FOV of the imaging system if I rotated the camera to the vertical position. So I ended up needing that feature on the first night of imaging with the system. The nebulosity between the major nebulae has some really interesting structure and dark features intertwined.

http://www.narrowbandimaging.com/M16_widefield_st10_pentax150_s2hao3_page.htm

I had just enough time to finish the entire series of Halpha, [SII] and [OIII] before the sun rose. Just barely!

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Posted on sf-bay-tac May 15, 2005 20:08:59 PT
Converted by report.pm 1.2 Sep 20, 2005 12:34:45 PT