Quote:
Originally Posted by Peter Ward
Looks like you got the pickles and relish in that one. A very fine hamburger indeed. 
|
I've still used yours as a bit of a benchmark, not quite there yet. I'd be interested to see how much the AO helps or whether it's the SNR on my end that's really limiting things. The ASI094 has a fairly sensitive and clean output but it has smallish pixels (4.8 microns) on a slow F/10 telescope with a bayer matrix throw in there as well.
Quote:
Originally Posted by DavidU
Wow Col, excellent image !!
|
Thanks Dave
Quote:
Originally Posted by Placidus
Unbelievably sharp.
Inspired by your work, Trish and I must experiment with some very short exposures, for the very brightest parts, and longer exposures to get the fainter parts.
You've already got quite a bit of relativistic jet showing.
What percentage of subs actually taken met the 1.8 sec arc threshold and went into the image?
|
Thanks Mike & Trish! You two are a part of the reason I wanted to get into longer focal length imaging, along with others like Peter, Mike, Lee and others obviously with their endless galaxy images
I managed 360x120 exposures over two nights and shot down as low as 45º as an end target. I had some 22 below 1.6; 6.1%. 146 below 1.8; 40.5% and for what I considered acceptable I've had 324 (90%).
Using all 324 with the weighting I've used for stacking (use both FWHM and star count) I end up with 1.71" around Cent A so I'm finding this afternoon that limiting it to the 146 best isn't really improving as much as I'd have thought. Doing a direct comparison between the two shows that the bottom of the stars is larger in the larger stack due to having some exposures in there reaching around 2.5" but they're not adding much due to the weighting being used.
Quote:
Originally Posted by graham.hobart
that is wonderful!! so sharp. Did you have any collimation issues with the mewlon?
|
Thanks Graham. When I was installing the corrector I had to remove the mirror, unscrew the original baffle tube and install the new one. I put the mirror back in and used a Tak Collimation Scope, spent a few minutes moving the secondary around a fair bit learning what moves what in what direction (so large movements). Spent maybe 15 minutes tweaking it on the kitchen table and haven't touched it since. That was nearly 12 months ago, several trips out to dark sites, in and out of the house and never felt the need to touch it.