Quote:or have I nailed it and now I can just go crazy getting data?
Adam AP Mach 1, Rob Miller TRI36L, Celestron 8" Edge HD Hyperion 17mm, Celestron 40mm Plossl, TMB 7mm & 9mm WO 66, Lunt LS60/B1200 PT, CG-5 Clone STF-8300m Pro Package, Honis-Modified Canon XS, Un-modded T1i, SSAG, TSOAG9, SX Lodestar
Lackawanna Astronomical Society
AstroTech Ritchey Chretien 8"
Williams Optics Zenithstar 80
Orion Atlas Eq-G
SBIG St-8300M Fw5-8300 w/Astrodon 36mm LRGB & Ha Filters www.SgAstrophotography.com
At the dark side of art, J-P Metsavainio, Finland LX200 GPS 12", SkyWatcher ED80, Canon 200mm EF f1.8L, Tokina 300mm AX f2.8, SXV-AO, QHY9, QHY8, QHY5, Lodestar BLOG:http://astroanarchy.blogspot.com/ IMAGE PORTFOLIO:http://astroanarchy.zenfolio.com/ FACEBOOK: http://www.facebook.com/jp.metsavainio
Quote:Hi Dave,You can get lots of good information about image scale and sampling through Google.Peter
Stellarvue SVR90T w/ SFF7 flattner
Celestron EdgeHD 800
Losmandy G11 / Gemini-II w/ opwb
Clear skies http://www.starkeeper.it http://stelledelcielo.blogspot.com/
Warren - Stargazing since the 60's! Scopes: ETX-LS6, ED80T, AT6RC, Lunt LS60T, C9.25 Mounts: Atlas EQ-G, Vixen Portamount II Cameras: Atik 314L+,DMK31AU03,SSAG, ASI120MC Filters: Astrodon LRGB, Orion HA, SII, OIII Acc: Orion 5 place Filter wheels x 2, Flatman Primary Imaging site: Bortle Scale Class 6 Red Zone http://astrobin.com/users/rigel123/
8" GSO RC with CSL Moonlite FocuserTelevue TV60isLosmandy G11 with Gemini 2 (with Ovision upgrade)
SBIG STT-8300m with Self Guiding filter wheel
A wide assortment of lenses for my Canon.
Quote:Binning Luminance is generally not a good idea because it will lose details. Binning color is fine like you always do.
Quote:Your FWHM is 2.67" which is good, however I would try to bring it under 2", given your location. That would be a significant step in added resolution, assuming seeing allows it.What is the FWHM of your focus stars? It will tell you if your collimation and focus is optimized as best as possible. If it is much smaller than 2.67", then you know its in the tracking or other factors like focus shift, flexure etc. limiting your long exposure FWHM/resolution.
Quote:Hi Sal,I am saying is if you can guide tight and focus well to get low FWHM of stars, then I do not see an issue of imaging at less than 0.5" if the seeing allows it. I don't like to image under bad seeing even if the image scale is between 1" and 2" because the results would be mediocore. It's a personal preference. Dave lives where there's very little to no light pollution and the seeing is normally good which is why I think he should stick to 0.46" image scale.Peter
You might take a look at Starizona's guides. They have one on Nyquist Sampling and how it relates to CCD astrophography that might help explain the concept better. It certainly explains it better than I could.