· 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 Equipment Discussions >> ATM, Optics and DIY Forum Previous   Index   Next   Threaded   Pages: 1 d_w newbie Reged: 06/18/07 Loc: Luhansk, Ukraine How to calculate lens radii by degree?       #5633528 - 01/20/13 04:41 PM Attachment (14 downloads) Edit   Reply   Quote Quick Reply   I have read in one article strange description of the lens: Thikness: 5mm Diameter: 75mm Radius: -389°; 125° This is not misprint, in other source were written "Radius: -389 degree; 125 degree" How to calculate lens radii by degree? I tried to measure radii in Solidworks by drawing (first lens in doublet), it samething about -340mm and 60mm. Edited by d_w (01/20/13 04:43 PM) Post Extras:       Mike I. Jones Carpal Tunnel Reged: 07/02/06 Loc: Fort Worth TX Re: How to calculate lens radii by degree? [Re: d_w]       #5634051 - 01/20/13 10:29 PM Edit   Reply   Quote Quick Reply   It doesn't follow any prescription convention, or even make sense. Can you post a link to the article? It looks like either a typo, or a mistake in character translation from one document format to another. Mike Post Extras:       Thomas Karpf Pooh-Bah Reged: 02/09/09 Loc: Newington, CT Re: How to calculate lens radii by degree? [Re: Mike I. Jones]       #5636801 - 01/22/13 12:31 PM Edit   Reply   Quote Quick Reply   Based on the shape of those curves, that is probably 389mm and 125mm. Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 6 registered and 34 anonymous users are browsing this forum. Moderator:  ausastronomer, richard7  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 301 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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