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] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Equipment Discussions >> Binoculars Previous   Index   Next   Threaded   Pages: 1 pcad Pooh-Bah Reged: 01/17/05 Posts: 1487 Loc: Connecticut Off center exit pupils?       #2596326 - 08/22/08 08:42 AM Edit   Reply   Quote Quick Reply   Hi All, I have a pair of 8x30 RP binos that I've never been 100% satisfied with. Both sides focus well and the alignment seems to be pretty good. I've noticed that when I look at the eyepiece end from arms length and try to line up the axis of the barrel with my eye the exit pupil seems to be off center. It seems to be inferior and away from the hinge. This is the case with both tubes. Is this responsible for my feeling there's something not quite right with these bino's or am I looking at an optical illusion? I haven't noticed this with other RP binos that I have. Peter -------------------- Peter Telescopes 25 - 318 mm Binoculars 15 - 88 mm Microscope 50x - 1000x Edited by pcad (08/22/08 05:38 PM) Post Extras:       EdZ Professor EdZ Reged: 02/15/02 Posts: 12485 Loc: Cumberland, R I , USA42N71.4W Re: Off center exit pupils? [Re: pcad]       #2596887 - 08/22/08 03:29 PM Edit   Reply   Quote Quick Reply   I've tested quite a number of binoculars with a tilted exit pupil path. Two out of 9 roof prisms were significantly tilted and one more moderately tilted. Four out of 11 8x porros were badly tilted. Two out of 14 10x porros were badly tilted. edz -------------------- Teach a kid something today. The feeling you'll get is one of life's greatest rewards. member#21 Post Extras:       Rich N Post Laureate Reged: 09/22/04 Posts: 5300 Loc: San Francisco Bay Area, Calif... Re: Off center exit pupils? [Re: EdZ]       #2596983 - 08/22/08 04:21 PM Edit   Reply   Quote Quick Reply   Those are really disturbing stats. Post Extras:       Simon S member Reged: 01/07/07 Posts: 99 Loc: Crawley West Sussex UK Re: Off center exit pupils? [Re: Rich N]       #2596997 - 08/22/08 04:27 PM Edit   Reply   Quote Quick Reply   I have come across a lot of low quality binoculars that suffer similar problems resulting from poor prism quality and alignment errors. I tend to find it is noticeable at low light more that in daytime viewing. Post Extras:       pcad Pooh-Bah Reged: 01/17/05 Posts: 1487 Loc: Connecticut Re: Off center exit pupils? [Re: Simon S]       #2597119 - 08/22/08 05:37 PM Edit   Reply   Quote Quick Reply   Thanks guys, My theory for this is that these binos needed significant adjustments in order to align the images. Since they are SP prism binoculars I imagine the alignment is done at the objective end. I find that it gives these binos a hard to define feeling of being not quite right. They're still usable since the image is sharp and I'm not seeing double with them, but they just won't be my first or second choice when I pick up a pair to use. The funny thing is that compared to most binoculars that I've seen in other peoples houses, these are would be an incredible improvement. Perhaps I'll donate them. -------------------- Peter Telescopes 25 - 318 mm Binoculars 15 - 88 mm Microscope 50x - 1000x Post Extras:       KennyJ Reged: 04/27/03 Posts: 10080 Loc: Lancashire UK Re: Off center exit pupils? [Re: pcad]       #2597137 - 08/22/08 05:51 PM Edit   Reply   Quote Quick Reply   < Perhaps I'll donate them. > Peter , perhaps you could donate them to someone whose eyes are off - centre relative to their brain ? :-) Kenny -------------------- Two eyes and a preference to use both Zeiss 7 x 42 BGAT Captain's Helmsman 7 x 50 Nikon 10 x 42 Superior E Swift Audubon Kestrel 10 x 50 Helios 15 x 70 Observation Strathspey 20 x 90 Televue 76 APO Zeiss 85 Diascope Helios 102 f5 refractor Various eyepieces barlows tripods mounts etc. Panasonic Lumix DMC - TZ5 digital camera Post Extras:       pcad Pooh-Bah Reged: 01/17/05 Posts: 1487 Loc: Connecticut Re: Off center exit pupils? [Re: KennyJ]       #2597236 - 08/22/08 06:44 PM Edit   Reply   Quote Quick Reply   Hi Kenny, Look for my pm. You're such a mind reader! Outside of those on this forum and others like it, most people would be perfectly happy with this bino. Just have to find someone who's not too fussy and wants or needs a binocular. -------------------- Peter Telescopes 25 - 318 mm Binoculars 15 - 88 mm Microscope 50x - 1000x Post Extras:       Wes James Carpal Tunnel Reged: 04/12/06 Posts: 2418 Re: Off center exit pupils? [Re: pcad]       #2597248 - 08/22/08 06:51 PM Edit   Reply   Quote Quick Reply   Of course, if we in this forum/as a group) weren't super fussy, we wouldn't all be here, looking for that last 5%, would we? I mean- can you imagine that some people actually just pick up their binoculars and look through them??? Wes Post Extras:       Pages: 1 Previous   Index   Next   Threaded   Extra information 15 registered and 20 anonymous users are browsing this forum. Moderator:  EdZ  Print Thread Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Thread views: 255 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

Cloudy Nights Sponsor: Astronomics