Getting Better
April 22nd, 2009
More time on M51 after making adjustments to the mount, it didn’t work quite as I had hoped as there is still some jitter in RA resulting in reduced exposure times from my expected target, but I was able to collect some data.
I took 50 frames plus 10 dark frames, and Deep Sky Stacker threw most of those out leaving me with 13 usable images. The problem as ever is drift leading to extended stars, but at least I have some noticeable progress.
[SinglePic not found]13 x 1 minute exposures,10 dark frames, ISO 1600, unmodified Canon EOS 1000D, Skywatcher light pollution filter.
I’ve no idea why DSS decided these were black and white images, that’s another thing to look into, they are definitely colour when viewed individually.
Lessons learned
- My adjustments to the mount were not perfect, mostly due to inexperience and incorrect technique. I had another look last night after reading up on the process and I’m happier with the result, the mount sounds and feels better. Still trying to balance between to tight and to loose is a matter of trial and error.
- Balancing is really important. I was able to reduce the streaking by moving the counter weight further down the shaft, producing more drag. It looks like I may have had it balanced to much on the scope side, the general rule of thumb is that the motor should be lifting up slightly rather than slowing down, I had things the wrong way round. The Vixen Sphinx is a pig to balance.
- Before turning off the lights in the shed check which plug your hand is on. Turning off the main power to the scope just when you started imaging is really annoying.
