You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> Film Astrophotography Previous   Index   Next   Threaded   Pages: 1 Anonymous Unregistered The telescopes f/number? *DELETED*       #2342272 - 04/21/08 01:20 PM Edit   Reply   Quote Quick Reply   Post deleted by CN_Admin Post Extras:       ClownFish Post Laureate Reged: 04/26/05 Posts: 5600 Loc: Islamabad, Pakistan Re: The telescopes f/number? [Re: ]       #2342677 - 04/21/08 04:31 PM Edit   Reply   Quote Quick Reply   You are correct with POINT sources like stars. Extended objects, like nebula is a whole other issue. The smaller the focal ratio the brighter extended objects will be. This is why I can capture the horsehead nebula in 15 minutes with my F/4 scope that would take an hour with an f/10 scope. CF -------------------- Learn all about POLAR ALIGNMENT with my Drift Method Tutorial and simulator!! Or visit my Foreign Service Blog! Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 1 registered and 1 anonymous users are browsing this forum. Moderator:  Suk Lee, Charlie Hein, knuklhdastnmr, ClownFish  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 234 Jump to *International Year of Astronomy 2009* -----   Global Coordination   Cornerstone Projects   Special Projects   Special Task Groups   Global Activities   National and Regional Activities   IYA 2009 in Africa   IYA 2009 in the USA*Announcements and News* -----   Cloudy Nights Announcements   Discussion of CN Articles, Reviews, and Reports   Beginners Forum   Celestial Events   Light Pollution*Equipment Discussions* -----   ATM, Optics and DIY Forum   Binoculars   Binoviewers   Cats & Casses   Classic Telescopes   Equipment   Eyepieces   Mounts   Observatories   Reflectors   Refractors    Celestron SkyScout and Meade mySky   Video and Electronically Assisted Astronomy*Astrophotography and Sketching* -----   Beginning Imaging   Film Astrophotography   DSLR & Digital Camera Astro Imaging & Processing   CCD Imaging & Processing   Solar System Imaging & Processing   Sketching   Astro Imaging/Sketching Contest *Observing* -----   General Observing   Planetary and Solar System Observing   Lunar Observing   Deep Sky Observing   Double Star Observing   Solar   Variable Star Observing and Radio Astronomy*Telescope Specific Forums* -----   Celestron NexStar    NexStar GPS / CPC Telescopes   Questar Forum   Meade ACF/RCX / LX / GPS    Meade ETX*Other* -----   Science of Astronomy & Space exploration   AstroWebsites   Space Rocks*Speciality Forums* -----   AstroArt   Astronomy Software & Computers   Stellar Media   Astro Outreach, Clubs and Star Parties*CN Feedback and Vendor Announcements* -----   Vendor and Group Announcements Home

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