· Get a Cloudy Nights T-Shirt · Submit a Review / Article    Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy 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] Forum Archives · Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing Previous   Index   Next   Flat   GeorgeFC member Reged: 03/27/09 Posts: 15 Re: A new focussing mask       07/22/09 03:15 PM Edit   Reply   Quote   Quick Reply:   Here is a DXF file for a Carey mask for a refractor (no central obstruction). http://www.btinternet.com/~gfcarey/m...o_obstruct.dxf Using Niels Noordhoek's simulation software it can be seen that a focus error of only 20 microns is clearly visible using a Carey mask. The gap between the right hand spikes is larger than that at the left. Post Extras       Entire thread Subject Posted by Posted on A new focussing mask GeorgeFC 03/27/09 01:38 PM Re: A new focussing mask camacker   05/29/09 02:33 AM Re: A new focussing mask GeorgeFC   05/29/09 07:30 AM Re: A new focussing mask camacker   05/29/09 02:44 PM Re: A new focussing mask GeorgeFC   05/29/09 03:56 PM Re: A new focussing mask GeorgeFC   07/04/09 07:07 AM Re: A new focussing mask lawrie   07/04/09 11:41 AM Re: A new focussing mask GeorgeFC   07/04/09 12:01 PM Re: A new focussing mask GeorgeFC   07/09/09 08:07 AM Re: A new focussing mask GeorgeFC   07/22/09 03:15 PM Re: A new focussing mask GeorgeFC   08/09/09 11:56 AM A new focussing mask shortcut? B. Hebert   08/10/09 02:39 AM Re: A new focussing mask shortcut? GeorgeFC   08/10/09 11:11 AM Re: A new focussing mask shortcut? GeorgeFC   09/12/09 09:39 AM Re: A new focussing mask WarrenS   05/29/09 08:17 AM Re: A new focussing mask GeorgeFC   05/29/09 10:33 AM Re: A new focussing mask WarrenS   05/29/09 12:11 PM Re: A new focussing mask Steve OK   03/31/09 08:08 AM Re: A new focussing mask GeorgeFC   04/01/09 04:16 AM Re: A new focussing mask Steve OK   04/01/09 07:50 AM Re: A new focussing mask JadeSmith   03/31/09 09:55 AM Re: A new focussing mask GeorgeFC   04/01/09 04:30 AM Re: A new focussing mask Strgazr27   03/27/09 02:19 PM Re: A new focussing mask zAmbonii   03/27/09 02:31 PM Re: A new focussing mask GeorgeFC   03/27/09 03:04 PM Re: A new focussing mask Nils_Lars   03/27/09 03:55 PM Re: A new focussing mask GeorgeFC   03/27/09 02:28 PM Extra information 15 registered and 8 anonymous users are browsing this forum. Moderator:  Charlie Hein, knuklhdastnmr  Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Rating: Thread views: 1346 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 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   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 CN Forums Home

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