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refractory
Pooh-Bah
Reged: 02/05/05
Posts: 1016
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As for zenith viewing, why doesn't somebody come up with larger, optical flat quality, dielectric coated mirrors, cheap. Solve a lot of problems about mounts. Have dialable adaptors holding them onto the ends of the binoculars. A nice improvement perhaps on Sky Windows? One could keep the binos horizontal, or whatever angle desired. Ho-hum...
Jess Tauber
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Steve Napier
Carpal Tunnel
Reged: 05/10/04
Posts: 1559
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Hi Joe,
I think the Eye-relief of the Tak"s is 19mm,Im not 100% sure on this but,if thats the case then its far too much for me.
The Miyauchis have 13mm eye-relief according to the site specs I read.
I believe the Tak"s have a 2.1 degree FOV compared to the 3 degree"s of the Miyauchis.
I really like the 45 degree angle too.
So Joe,there"s 3 reasons why I would buy the Miyauchi"s over the Tak"s.
Steve.
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IDONTSEEIT
scholastic sledgehammer
Reged: 05/04/03
Posts: 901
Loc: NYC
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OK, OK, Steve, I give up!  
My motivation for trying to quell, or at least dampen, your enthusiasm for the Miyauchis is purely selfish. I just don't want you unleashing your, quite formidable and unyielding, satyrical wrath on me, like you do on KJ daily, if you end up being disappointed by them, or even just finding much more at fault with them than I do/did.  
That, and the disparity in cost ratio of the two bins being discussed, between both of our fine homelands. 
Good luck with them, when are they scheduled to arrive? 
--------------------
Joe,
C8 OTA on UA Unistar Heavy Deluxe
SV-102V on same UA Unistar Heavy Deluxe(not at the same time)
WO-Megrez 80-II ED on UA Microstar Basic
Orion 80ED on same UA Microstar Basic(also not at the same time)
Miyauchi Bs-60ic "Pleiades" 22X60
Orion UltraView 10X50's
Orion MiniGiants 12X63 & 15X63
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IDONTSEEIT
scholastic sledgehammer
Reged: 05/04/03
Posts: 901
Loc: NYC
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Hi Jess,
Yeah, I considered a skywindow type mount, but of the ones currently available, I've read alot of mixed reviews, with nothing overly positive about any of them. From what I remember, most discussed problems; with the "flatness" of the mirrors, spurious reflections(and since I'm in a heavily light-polluted area it might be awful), double star images, dewing, poor images with magnifications exceeding ~10-12X(which would be/is the primary need for one), dewing of the mirror, and the easy scratchability of the mirror.
I think, if I'm reading your post correctly, using a seperate mirror for each objective would be a collimation nightmare, to say the least.
I think a nice, relatively inexpensive, mount could be built around a large, single, 1/4-wave, dielectric(read: easily cleanable and relatively scratch-resistant), reasonably priced mirror, but then adding a dew-removal/prevention system might make it no longer reasonably priced/inexpensive. 
I believe the skywindow, and similar mirror-mounts can be mounted on a tripod and pointed to any angle/orientation for comfort of viewing, but at least following the reviews currently available, they may not be useable for the higher mags one might need them for, and they are hardly reasonably priced at the moment. This doesn't make them a very good value, IMHO.
The hunt continues I suppose, as you said, Ho-hum!! 
--------------------
Joe,
C8 OTA on UA Unistar Heavy Deluxe
SV-102V on same UA Unistar Heavy Deluxe(not at the same time)
WO-Megrez 80-II ED on UA Microstar Basic
Orion 80ED on same UA Microstar Basic(also not at the same time)
Miyauchi Bs-60ic "Pleiades" 22X60
Orion UltraView 10X50's
Orion MiniGiants 12X63 & 15X63
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refractory
Pooh-Bah
Reged: 02/05/05
Posts: 1016
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Ebay has various big optical flats (often from Surplushed) every week. A big mirrored 12 inch round one went for just a few hundred dollars the other day. Wrong shape for me, though. Some of the huge rectangular test flats cost thousands.
I guess ideally your mirror should be all one piece.
I've been toying with the notion of making very thin flats using nonabrasive chemical techniques and waterjet polishing. I've been told it makes for much smoother surfaces, with none of the cuts, digs, etc. one sees in conventional mirror finishes. As with concave mirrors, the mounting would carry most of the burden of holding the shape well.
As for dewing, there shouldn't be any reason one couldn't design a cowling-like dew shield for the mirror, and a drainage system. The same shield might also help to block stray light. Cleaning and protection via the old fashioned collodion method- solution polymerizes for storage when not in use, then simply peel away with all the dirt and other stuff. Fresh, clean mirror every time.
Jess Tauber
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IDONTSEEIT
scholastic sledgehammer
Reged: 05/04/03
Posts: 901
Loc: NYC
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Isn't collodion really expensive???? 
--------------------
Joe,
C8 OTA on UA Unistar Heavy Deluxe
SV-102V on same UA Unistar Heavy Deluxe(not at the same time)
WO-Megrez 80-II ED on UA Microstar Basic
Orion 80ED on same UA Microstar Basic(also not at the same time)
Miyauchi Bs-60ic "Pleiades" 22X60
Orion UltraView 10X50's
Orion MiniGiants 12X63 & 15X63
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Steve Napier
Carpal Tunnel
Reged: 05/10/04
Posts: 1559
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Hi Joe,
I have not ordered these as of yet.I want to find much more about them first.
Rest assured though If,I decide to order a pair in the future and,Im not happy with them,I will blame Kenny.
As for daily tirade against Kenny,why not?
He deserves it.
Steve.
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