· 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 roscoe curmudgeon Reged: 02/04/09 Loc: NW Mass, inches from VT Rotating/tuning objectives?       #5601504 - 01/02/13 04:06 PM Edit   Reply   Quote Quick Reply   I have a couple of 60mm scopes that, I suspect, could present better images if the crown and flint were better adjusted..... how do folks rotate objectives for testing without taking them completely out of the cell each time? My thought was to stick a tab of tape on and with the retaining ring loosened, use it as a handle, but something 1/2" square would, it would seem, degrade the image...... any better ideas? Thanks, Russ Post Extras:       dan_h Carpal Tunnel Reged: 12/10/07 Re: Rotating/tuning objectives? [Re: roscoe]       #5601605 - 01/02/13 05:09 PM Edit   Reply   Quote Quick Reply   With the assembly pointed vertical, loosen the retaining ring and use a simple suction device to lift the crown element and rotate it. A section of rubber hose smooth cut and a line you can suck from should do the job. dan Post Extras:       punk35 sage Reged: 01/26/05 Loc: lower michigan Re: Rotating/tuning objectives? [Re: dan_h]       #5601700 - 01/02/13 06:16 PM Edit   Reply   Quote Quick Reply   I used a small suction cup from a window thermometer Post Extras:       roscoe curmudgeon Reged: 02/04/09 Loc: NW Mass, inches from VT Re: Rotating/tuning objectives? [Re: punk35]       #5602209 - 01/03/13 12:08 AM Edit   Reply   Quote Quick Reply   Thanks, guys! I'm going to try Dan's method first - I like that it is instantly removable from the lens face...... and if I don't have luck with that system, I think my son might still have some toy 'bullets' that have suction cups about 1/2" dia on them, and I'll try one of them. Russ Post Extras:       DAVIDG Post Laureate Reged: 12/02/04 Loc: Hockessin, De Re: Rotating/tuning objectives? [Re: roscoe]       #5602591 - 01/03/13 09:27 AM Edit   Reply   Quote Quick Reply   If you want to do job right, get yourself an optical flat. Since your working with 60mm objectives a 2-1/2 to 3" diameter one will work perfectly and it doesn't need to be coated. You can borrow the secondary from a large newtonian. Then set the lens up in double pass mode using a ronchi screen. The line should be dead straight, if not you can rotate one element against the other to find the exact position were they are the straightest. No guessing and no waiting for clear weather to do star testing. - Dave Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 5 registered and 15 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: 360 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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