Noch ein Nachtrag zum Vixen FL 90 S - es gibt einen Kurzreview von Todd Gross zu diesem Teleskop, den ich hier wiedergeben möchte:
"Jay Reynolds Freeman had raved about this scope, so an Astromart ad caught my attention. The price was so high that I knew either the seller was overpricing it, or he knew he had something special. Before I get to the incredible performance, let me go through the negatives. The focuser is a bit flaky, with some sticky areas, but this older version is 50mm wide, so it accepts 2" eyepieces when used with the Lumicon adapter (current version of this and the 102mm apparently do not have true 2" capability) Also, the scope is so lightweight, that I wondered if it is built as sturdily as the similar sized Takahashi FS78-FC76. Also, I am having trouble seeing how many baffles there are, I think the TAKS may have more.
Now for the performance. Unbelievable, it's not that this scope is outdoing my larger aperture scopes on planets, it's that I am even having this discussion at all! This is, after all, only a 90mm scope. Yet the performance on the planets is big league, with the Cassini division on Saturn for instance available each and every viewing session even in mediocre seeing (1997). The seller indicated that Cassini was visible last year (1996) which would put it at or above the A/P Traveler in planetary performance ... and the reason I bought it. The star test is perfect, and colorless inside and outside of focus, as were the images of brightest stars. NO COLOR. Despite my claim of excellence in the second set of optics on my Brandon 80mm ... this scope is in another class. Deep Sky views appear roughly 25-50% as bright as the 80mm, at high power, (which somewhat exceeds the math) but that's hard to quantify. SIX STARS were viewed in the Trapezium in Orion, although only with straining averted vision. I did know where to look, but at least one of the stars surprised me by being tighter in than I had expected. Jupiter was very crisp ... but the lack of light gathering will likely hinder high power performance on very subtle features. I could make out some festoons, the GRS was not available, but the dark red ovals at longitudes 270/288 were very crisp and readily visible. Banding on Saturn was a cinch, and as I mentioned the Cassini division was a snap from 120-270x. Daytime peformance is crisp through 400-500x. What I am most impressed with is the cleanliness of the airy disk. Very little energy goes into the diffraction rings at high power-in focus-star testing, meaning my splits are very clean, and dimmer than expected stars are seen. Even with a high deck of clouds, I was able to split M13 to individual stars for instance, limiting magnitude was around 4.3. This is a super-lightweight scope (maybe 7 lbs) that works very well on the Super Polaris, which is overkill, but can even work with certain bogen tripod/head combinations. It is 32" long with a 4" dewshield which can be removed during travel. Careful airline portability is an option if one gets a nice case. I have no idea if the current units (80-90-102mm) have this kind of performance. I know of 2 other 1980s units that do. The only down side is the aperture, the Takahashi 5" will resolve much more of the tough star clusters, and probe deeper and show more color (real color, like on the Orion nebula). An 8" SCT , same thing. For a small scope though, this optics are unbeatable, and will allow some serious lunar/planetary observation akin or at least approaching the big boys.
2001 Update: I have received two more of these fine refractors and have thrown them against the Sky 90. One has what looks to be approx. 1/6th to 1/8th wave undercorrection, and the other perhaps 1/9th wave overcorrection, nearly perfect. Both had similar views to the Sky 90 using it's "extender-q" option. Performance was almost identical. Still testing.
PROS: One of the best performing 90mm scopes ever. CONS: Bit large for airline (overhead) travel.
Hier ist die Originalquelle:
http://www.newxspotters.bizlan…rman/scope.htm#thirty-two
Dort finden sich noch weitere interessante "Minireviews" einer Vielzahl von Teleskopen. Gibt zwar seit längerer Zeit keine neuen Einträge mehr, aber die vorhandenen sind sehr interessant. Auch sehr exotische Teile bekommen da ihr Fett weg. 
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">Zitat:<hr height="1" noshade id="quote"><i>Original erstellt von: Hayabusa</i>
<br />Hallo Christoph,
tatsächlich? Ich dachte immer den früheren FC 100 gab es nur als f/8. Heute gilt ja f/8 schon als langsam.
Schon wieder was gelernt.
Beste Grüße,
Uwe
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
