Seth Thanks for the assessment. I checked all around my binoculars and cannot even find the collimation screws so often mentioned on this topic. I think I'll add a pair to my Christmas list... Dion ________________________________ From: Seth Jarvis <SJarvis@slco.org> To: 'Utah Astronomy' <utah-astronomy@mailman.xmission.com> Sent: Tuesday, October 30, 2012 9:17 AM Subject: Re: [Utah-astronomy] Binocular repair? The conversation about repairing damaged binoculars included a reference to a book: "Choosing, Using and Repairing Binoculars" by J. W. Seyfried, available through http://www.universityoptics.com/books.html The discussion was interesting so I ordered the book ($20) and it arrived in yesterday's mail. First, I think it was packaged by someone who previously had a career packaging Fabergé eggs in preparation for the apocalypse. Second, it's a completely delightful book. Mr. Syfried is a man who clearly has been in love with optics pretty much his whole life. I spent 30 minutes last night just flipping through it, looking at his illustrations and diagrams and reading his descriptions of binoculars and binocular repair methods. His writing is very personal and easy to read. Third, the book is a bit hit-and-miss. For example, in his "Frequently Asked Questions" section he gives a compelling explanation of why Porro prism binoculars are generally a better bargain than roof prism binoculars, and much easier to maintain and repair, but he never explains what "roof prisms" are and how they differ from "Porro prisms," and neither term appears in the book's glossary. I suspect there will be other places in the book that will only make sense after looking some things up on Wikipedia. Finally, and most important, his chapter on re-collimating damaged binoculars makes it abundantly clear that _if_ your binoculars are constructed in such a way as to make re-collimating even possible, and _if_ you have the bench, tools, equipment, skill and time to tackle the project, and _if_ the prisms and lenses themselves aren't damaged, then you stand a pretty good chance of getting your binoculars back in proper working order. The edition I was sent was published in 1995, so I don't know if the companies referenced in the back of the book as providers of optics repair parts and services are still around. Interesting book, totally worth the twenty bucks, but I'm now convinced more than ever that for 99% of us, binoculars that have gone wall-eyed are just the universe's way of telling you it's time to get a new set of binoculars. Seth -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Tuesday, October 23, 2012 11:01 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Binocular repair? Dion: If there is no structural damage to the binocular, it is most probable that one (or both) of the prism clusters has become knocked out of alignment. In the good old days, most decent binoculars had access holes in the housing to allow you to get to the adjustment screws. Many don't do this anymore, and it is as Seth posted, it is often cheaper to simply replace them than to have them re-collimated. That said, some makes and models can still be adjusted. On more than one occassion I have re-collimated the ubiquitous Chinese-made 15x70mm binocular sold as Celestron, Oberwerk, Galileo, Bear, Brunton, etc. They are all the same binocular made on the same assembly line, with the only differences being labeling, the outer rubber coating and eyeguards, and slight coating differences on the optics. There used to be a DIY article on Cloudy Nights that detailed the procedure, I'm not sure if it's still there. It's a trial and error method and can be very time consuming, but it has worked for me. I'm also not convinced that the adjustments, once made, will be as robust as the factory setting since they use a putty-like substance to hold the prisms in adjustment that hardens upon application. You have to break that loose to adjust the prism clusters and once re-aligned you'd need to apply something similar to help hold them there. You have to know where the adjustment holes are for your model and to access them it often means peeling-back the rubber "armor" to get to them. And of course you have to stick the rubber back down when done. The professionals use a dual-barrel collimator. I don't think anyone in Salt Lake has one anymore. Gallenson's did decades ago. University Optics might be a good place to call. Jan Seyfried is a binocular expert and has written on the subject. He might even have a collimator and if he can't or won't recollimate them, he might be able to suggest a shop that can. Bill Cook (former ATM Journal editor) is also a career optician with a Navy background and if you can find his number, he might be able to help, as well. Actually I'm not sure if Bill is still living but you never know. On Tue, Oct 23, 2012 at 6:58 AM, Dion Davidson <diondavidson@yahoo.com>wrote:
Does anyone have suggestions on where I can take my Bushnell 12x50 binoculars for repair? The eyes don't line up anymore, and nothing I do with the knobs and dials seems to fix it. I don't know if they got dropped or what. Each eye seems OK independently, but together they create nothing but headache because the two images are not aligned. Thanks, Dion
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