got some new data on NGC3621 to be added to that from last year (I was somewhat disappointed with last year's effort). Rejected the subs with poorer seeing - 62 of them - so nothing above about 2.6 arcsec FWHM was kept (as measured by PI) and some of the subs were down below 2 arcsec. The resulting stack of 200 subs (mix of 4 and 5 minutes) was very easy to process - mild deconvolution, stretch and background flattening. I think that quite vigorous pruning of data pays off and, where it makes sense, will be doing so more aggressively in future.
Fantastic job Ray. The main galaxy looks wonderfully resolved, numerous background galaxies too
hi Colin. thank you. yes, the background galaxies are quite a varied lot in this region.
Quote:
Originally Posted by TR
Vigorous pruning in the garden pays off as well. That is a very nice result Ray.
thanks Terry - getting rid of the lesser subs seems to be beneficial overall.
Quote:
Originally Posted by RickS
Lovely, Ray! A great improvement over your previous rendition which wasn't too shabby either.
I have been weighting my subs on FWHM and trying to keep as many as possible. It's so hard to throw data away
Cheers,
Rick.
Thanks Rick. I am coming to the conclusion that once the low res stuff is included it cannot be unscrambled effectively. I also hate throwing away data - am doing a lot of thinking about how to re-include some without stuffing up the good bits.
Quote:
Originally Posted by alpal
Hi Ray,
That's perfect.
It's really sharp & clear.
The 10" f4 does it again - Well done.
cheers
Allan
thanks very much Allan. yep, the optics seem to be pretty good (thankfully).
Quote:
Originally Posted by PRejto
Really nice!! I love that little face on spiral at 11 o'clock. This is an inspiring image. Great!!
Peter
thanks very much Peter. Yes, that spiral is a handsome galaxy - need some more resolution....
That's a beautiful field Ray. Love the colors. Some very good details in the spiral structure. I also like that little face on at 10 o'clock. Good stuff.
Thanks Justin. nope, not a perfectionist - just annoyed that I cannot do better.
Quote:
Originally Posted by Geoff45
That's a great image Ray. It's a really difficult target as I found from personal experience.
Pruning is hard at first, but I found that once you get into it it gets easier and the result justifies any angst about rejection.
Geoff
thanks Geoff. It's a beautiful object, but the dim bits are hard to get. Removing sub-standard data helped, even though it does hurt to throw away 5 hours of photons.
Quote:
Originally Posted by rustigsmed
awesome, loving the outer arm extensions - nicely done!
Another really nice galaxy image Ray, although faint its a very magestic galaxy, an enjoyable view throwing lots of data huh?..show off but in the end good seeing always beats processing.
Mike
Last edited by strongmanmike; 05-03-2016 at 03:14 AM.
Another really nice galaxy image Ray, although faint its a very magestic galaxy, an enjoyable view throwing lots of data huh?..show off but in the end good seeing always beats processing.
Mike
thanks Mike. It isn't often that I have enough data that I can throw stuff away, so I wanted to try out some fairly heavy culling. I haven't done a side-by-side comparo, but my impression is that the culled data produces a better image than the whole thing + heavier deconvolution. Of course, the extremities of this galaxy are very faint, so there may be value in Rick's method of adding in lower res data with lower weights.
As you say, nothing beats good seeing - and there hasn't been very much of that just lately.
A very nice image Ray. Colour balance looks near perfect to me. The smooth background is also a nice addition to the image. Well done.
thanks very much Paul - appreciated. The outer reaches of this are dim and it needed more data than normal to retain the full detail in that part of the image.
but in the end good seeing always beats processing.
