Search found 426 matches

by oopfan
Mon Mar 04, 2019 12:47 am
Forum: Gallery
Topic: NGC2244, Rosette Nebula, Altair 183M, 20x180s
Replies: 2
Views: 101

Re: NGC2244, Rosette Nebula, Altair 183M, 20x180s

Pushing the 183M to the max!
by oopfan
Mon Mar 04, 2019 12:44 am
Forum: Gallery
Topic: M42/M43/NGC 1977, Altair 183M, 60x60s
Replies: 2
Views: 129

Re: M42/M43/NGC 1977, Altair 183M, 60x60s

It amazes me that you can capture that much nebulosity so low to the horizon given your latitude and light pollution constraints.

Brian
by oopfan
Mon Mar 04, 2019 12:41 am
Forum: Gallery
Topic: M42/M43 Narrowband
Replies: 3
Views: 129

Re: M42/M43 Narrowband

Really nice, Nick!

Is it Hubble Palette?

Brian
by oopfan
Mon Mar 04, 2019 12:36 am
Forum: Gallery
Topic: What long exposures do.
Replies: 5
Views: 134

Re: What long exposures do.

A really awesome image, Rob! Light pollution should never be an excuse not to experiment with longer exposures. Light pollution is signal just like nebulosity. While it is true that you can't image nebulae fainter than light pollution, you will get greater contrast of the visible parts when exposure...
by oopfan
Thu Feb 28, 2019 12:10 pm
Forum: How do I?
Topic: FWHM units?
Replies: 3
Views: 144

Re: FWHM units?

Hi cshine, I had to edit my reply after noticing that the CCD Suitability Calculator explicitly uses FWHM_arcsec in the "Seeing" dropdown box. I've only Live Stacked once in my life so I can't say with certainty if the 'FWHM Score' is the average or maximum FWHM_pixels or some other function. For it...
by oopfan
Thu Feb 28, 2019 2:28 am
Forum: How do I?
Topic: FWHM units?
Replies: 3
Views: 144

Re: FWHM units?

Hi, It is in pixels. You can convert FWHM in pixels to FWHM in arc seconds with this formula: FWHM_arcsec = FWHM_pixels x ( pixel_size_um / focal_length_mm) x 206.3 And the other way around: FWHM_pixels = FWHM_arcsec x (focal_length_mm / pixel_size_um) / 206.3 My camera: pixel_size_um = 2.9 My teles...
by oopfan
Wed Feb 27, 2019 2:45 am
Forum: General Discussions
Topic: confused and frustrated
Replies: 2
Views: 214

Re: confused and frustrated

Hi, Terrestrial and astronomical targets focus differently. I agree with Robin, use the Moon, then take a tape measure and measure the distance from your camera to any fixed point on the telescope tube. Jot it down and keep it safe. Someday you may want to do terrestrial again, or perhaps you want t...
by oopfan
Tue Feb 26, 2019 11:25 pm
Forum: How do I?
Topic: In need of a SharpCap tutor
Replies: 49
Views: 2147

Re: In need of a SharpCap tutor

Joe, Have you looked into joining a local Astronomy club? Here is one that is a 20 minute drive away from you: https://westchesterastronomers.org/ Here is a list of clubs in New York and New Jersey: https://www.go-astronomy.com/astro-clubs-state.php?State=NY https://www.go-astronomy.com/astro-clubs-...
by oopfan
Mon Feb 25, 2019 2:49 pm
Forum: Live Stacking
Topic: Binning and stacking
Replies: 12
Views: 463

Re: Binning and stacking

Nick,

Minos images in narrowband with 30s exposures. There may be some helpful info in his post:

viewtopic.php?f=16&t=1124

Brian
by oopfan
Mon Feb 25, 2019 2:25 pm
Forum: Live Stacking
Topic: Binning and stacking
Replies: 12
Views: 463

Re: Binning and stacking

Hi Nick, You must have a very fast scope to capture anything in Ha with 30s exposures. I take 200s exposures at f/5.9. According to calculators I've used I need to go longer because the signal-to-noise ratio is barely acceptable: https://astrotuna.com/soul-nebula-in-ha/ Here's another but still a wo...