How many stops is 256x? On Sat, Jul 3, 2010 at 12:57 PM, Brendan MacRae <[email protected]> wrote: > > > > > ----- Original Message ---- >> From: Anthony Farr <[email protected]> >> To: Pentax-Discuss Mail List <[email protected]> >> Sent: Sat, July 3, 2010 3:58:31 AM >> Subject: Re: Strange "Asahi NC Takumar 3,3/300mm Pentax M42" on Ebay >> >> "The mounting the tube seems also an original." > > Are you sure about >> that? Compare the pictures at >> AOHC: > > http://www.aohc.it/cameras/nocta.jpg > and, > http://www.aohc.it/images/sp40.jpg > > to >> the picture at the >> auction: > > http://i.ebayimg.com/11/!Bw0VCdQBGk~$(KGrHqIOKioEwPgB+i)hBMKt40,WIw~~_12.JPG > > You >> can see that the historic pictures show a much shorter tube > between the wide >> part of the lens and the body of the image > intensifier, with no obvious >> tapering or visible bright metal. The > ebay lens doesn't have any place >> where an image intensifier could be > placed according to the old >> pictures. > > regards, Anthony > > The Nocta is described pretty well in Oosten's "The Ultimate Asahi Pentax > Screw Mount Guide 1952-1977," pgs 255-256. From the three pictures in this > book, it appears as though the eBay lens is complete minus the larger > focusing handle. A rare unit indeed. > > The description of lens from the book: > > "The lens is a highly specialized Takumar 1:3.3/300mm for Infrared > photography. The minimum aperture is f/22, the angle of view is 8 degrees. It > was supplied with a 256X Neutral Density filter (42mm) for use under daylight > conditions. The actual front of the lens measures 300/3.3 = 91mm in diameter > of which only the central part is used in daylight." - pg 255. > > -Brendan > > > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. >
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