Late last night patchy clouds came in so I dumped the usual long exposure pain, and took this pic through sucker holes with short exposures. I only got 1 hr total in before shut down, at about 2am.
Its very small, but also bright, especially OIII, huge ADUs with just 2 min subs . I was suprised, I dont think ive ever got away with 2 min NB subs on anything !.
Anyway, this is 4 off 10min 3nm Ha subs, 6 off 2 min OIII and 2 off 5min SII (both 6 nm). Mapped as LRGB (hubble), all at bin 1 . SII was a joke, almost nothing.
I was lucky enough to find a bright enough guide star to fire up AO8 guiding at 2hz. The guide star was mag 10, 0.25sec exposures is unusual for this mag (I think), so the seeing must have been quite good, despite the full moon and bright clouds everywhere.
Guideing error was about 0.2 arc/secs RMS although the pk/pk could have been 1 arc/secs or more.
The Saturn neb is some 16 arc/secs in diameter, about 25 pixels at my image scale and FL(0.68 arc secs), so this image is VERY cropped, the raw subs were fairly blocky before processing, hence the focus doesnt look very flash at all .
Anyway, given the FOV it came out OK I think, AO saved my ass here from a even more blurry mess .
I'm tempted to take the C11 out of mothballs and doing some imaging at >2800 FL.
Steven
Oh yeah, do it . I miss the 12" at 3m. 10" is a suprising increase in exposure time.
Its hard, but over 2m is well, differenter and more challenging and obviously betterer. Croping the hell out of pokey refractor pics is well, marginal, and way too much harderer, even on an AP
Oh yeah, do it . I miss the 12" at 3m. 10" is a suprising increase in exposure time.
Its hard, but over 2m is well, differenter and more challenging and obviously betterer. Croping the hell out of pokey refractor pics is well, marginal, and way too much harderer, even on an AP
Very cool! Much more dedication shown when imaging long FL than cropping a widefield shot!
Bravo chap!!
Ps - put the 12" up on the PME, sell the 10" RCOS.. then your costs are not so extreme, and the results would be similar if not better given local sky conditions.... Just a thought..
Very cool! Much more dedication shown when imaging long FL than cropping a widefield shot!
Bravo chap!!
Ps - put the 12" up on the PME, sell the 10" RCOS.. then your costs are not so extreme, and the results would be similar if not better given local sky conditions.... Just a thought..
Thanks Alex
Actually, im kidding, ive seen some very good close ups on refractors, and given the apature, must be much harder
Yes, ive considered putting the 12" up, but setting up everything again (image train adaptor hell, pointing map, FOV indicator, focus max etc) makes it just too hard on a whim, and the RCOS is soo stable.
The last time I tried the Meade, there was something very wrong with images (with the long image train, same as the RC plus a focuser, stupid long), havent worked that out yet, could be way past the back focus, whatever it is on an SCT, cant find out. Ive seen an image train that long on Astro anarcys site, but with a FR, seemed to be fine, although counter intuative (doesnt a FR reduce back focus?). Fitting the FR is more adaptor hell, its starting to get unwieldly and unstable (the ST10/filter is way heavier than a QHY).
mmm, come to think of it, I must ask Stuart how he does it.
You can see in the image what looks like the neb is starting to go middle elliptical with the bright rim starting to push out the halo at the bottom and the top.
Hmmm?...at first I thought you had done the ol' looks like detail but is really just processing artifacts trick again ..but nup, comparing to Hubble shots I think the mottling in the halo is indeed (at least mostly) real , nice job.
Now I would like to see a crop of just the inner ring too please...and maybe the pointed ends of the inner oval, or.....oh sorry your field is already sooooo small you can't do that huh? DOH
Beautiful!
I tried the same object only to realise I' dforgotten to put a card in the DC!
Images like this only re-inforce my opinion: "Leave it to the pros!"
Thanks for posting.
. I was suprised, I dont think ive ever got away with 2 min NB subs on anything !.
.
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(the ST10/filter is way heavier than a QHY).
