----- Original Message -----
From: "Daniel J. Mitchell" <DanielMitchell@xxxxxxxxxxxxx>
> Just been looking at pages listing all the lenses I'd like, and I noticed
> that the brightness seems to peak at 50mm.
Even Leica tops out at f1 with its 50mm Noctolux for the M series
rangefinders. (Understand a f1 would be just about impossible to focus with
an SLR.) I seem to remember hearing that Vivitar had some kind of super-fast
Vivitar One series lens which was supposed to be f0.95 or some unbeliveable
speed. (Have no clue if this is accurate or not, never saw the lens.
Anyone?)
I am guessing that it has something to do with the optics and correcting all
of the aberrations at such a wide f-stop and since 50's sell the most, maybe
that's where they put the money. (?)
I find it interesting that medium and large format lenses always seem to be
even slower, more in the 2.8 for medium format, and 5.6 or even 8.0 for
large format. (210mm f5.6 Schneider APO-Symmar for example). I am guessing
(again) that Schneider has them optimized for optic quality and lets the
f-stop fall where it may versis the handheld world of 35mm.
> I can understand why it'll fade off as the lens gets longer, because
> there's more glass there -- but why isn't the 16mm f0.6?
Thinking about how massive the Olympus 8mm f2.8 is, I went looking for a
faster full-frame fisheye. Didn't find one, but I did find a Ni*on 6mm
(ack!) f2.8 fisheye. (5.2kg weight) The lens dwarfs the F3 attached to it.
Unfortunately, they don't have a photo showing the len's 220 degree field of
view, but rather a 8mm.
http://www.mir.com.my/rb/photography/hardwares/speciallenses/6mmfish1.htm
The "fastest" long lens (telescope camera actually) that I know of is a
Celestron 8" (aperture) f1.5 Schmidt camera with a focal length of 300mm.
Without any shutter, it is hardly suited for terrestrial use, but great for
astronomy. http://www.fayettevillenc.com/backyard/schmidt.htm
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|