· Get a Cloudy Nights T-Shirt · Submit a Review / Article Click here if you are having trouble logging into the forums Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> Beginning and Intermediate Imaging Previous   Index   Next   Threaded   Pages: 1 WhitenerJ professor emeritus Reged: 02/06/12 Loc: Waxahachie, Texas Nebulosity fine focus?       #5676640 - 02/12/13 09:43 PM Edit   Reply   Quote Quick Reply   Ok what numbers should I be aiming for when fine focusing in Nebulosity? Like the Max and HFR? Also what do you look for on the graphs? Jason Post Extras:       Mike7Mak Pooh-Bah Reged: 12/07/11 Loc: New York Re: Nebulosity fine focus? [Re: WhitenerJ]       #5676688 - 02/12/13 10:08 PM Edit   Reply   Quote Quick Reply   I've never been able to make sense of the graph. The actual numbers depend on the image scale but you want the HFR as low as possible and Max as high as possible. Nights with poor seeing can make fine focus a pain to use. I used it for a long time but it always left a nagging doubt as to whether I actually got the lowest HFR possible. A lot of time was spent going in and out of focus trying to minimise HFR. I've since gone to a Bahtinov mask. There's no comparison. The mask leaves no doubt about when you've reached proper focus. Post Extras:       Charlie B scholastic sledgehammer Reged: 03/22/08 Loc: Sterling, Virginia Re: Nebulosity fine focus? [Re: Mike7Mak]       #5677152 - 02/13/13 07:47 AM Edit   Reply   Quote Quick Reply   I use both the Bahtinov mask and Nebulosity's fine focus. The mask gets you on when you have a bright star, but when doing Ha or OIII imaging, and switching filters, I need Nebulosity's fine focus to get the best focus. In good seeing, The FWHM is less than 2 pixels, usually 1.6-1.8 with my 800 mm fl and in bad seeing can be greater than 3. Charlie B Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 3 registered and 15 anonymous users are browsing this forum. Moderator:  Undermidnight, fishonkevin  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 138 Jump to *Announcements and News* -----   Cloudy Nights Announcements   Discussion of CN Articles, Reviews, and Reports   Celestial Events*General Astronomy* -----   Beginners Forum   General Observing and Astronomy   Outreach   Light Pollution*Equipment Discussions* -----   ATM, Optics and DIY Forum   Binoculars   Binoviewers   Cats & Casses   Classic Telescopes   Equipment   Eyepieces   Mounts   Observatories   Reflectors   Refractors    Video and Electronically Assisted Astronomy*Astrophotography and Sketching* -----   Beginning and Intermediate Imaging   Film Astrophotography   DSLR & Digital Camera Astro Imaging & Processing   CCD Imaging & Processing   Solar System Imaging & Processing   Sketching   Astro Imaging/Sketching Contest *Observing* -----   NEO   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*Speciality Forums* -----   Arizona Science and Astronomy Expo   NEAF (Northeast Astronomy Forum) and NEAIC (Northeast Astro Imaging Conference)   AstroArt   Astronomy Clubs and Star Parties   Astronomy Software & Computers   AstroWebsites   Science! Astronomy & Space Exploration, and Others   Space Rocks   Stellar Media*Swap and Shop* -----   Shop and Swap Audio Components*CN Feedback and Vendor Announcements* -----   Vendor and Group Announcements*International Year of Astronomy 2009 - Forums are now closed.* -----   IYA Archive Info CN Forums Home

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