1000mm f12.5 ED

[André Langevin]

I see that Pentax has a combo (PF-80ED spotting scope + PF-CA35 adapter) that makes a light 1000mm lens.
The Pentax PF-80ED is seen as the reference spotting scope from what I've read.

With the PF-CA35 adapter, it makes a 1000mm f12.5 lens that weights 1850g with a min. focus dist of 5.8m. The 1000mm f/11 mirror weights 2300g and has a min. f. d. of 8m (and exhibits "donuts" highlights) ; the 1200mm f/8 ED weights 8500g and has the same min. f. d. (and costs an arm and a leg).

The combo can be had for 925 US $ around here (625 for the scope and 300 for the adapter), which is lower than in USA. I am tempted to replace my SMCT 1000mm with this. It's one and a third stop slower but is three times lighter and must have little chromatic aberrations.

Anybody tried such a kit?


On a body, it looks like:

http://www.astroarts.co.jp/hoshinavi/magazine/nikki/index-j.html


From friendly russian Penta-club site:

Asahi Optical Co., Ltd. is pleased to announce the marketing of the PF-CA35 Camera Adapter as an exclusive accessory for the Pentax PF-80ED Spotting Scope. Mounted between the PF-80ED and a Pentax 35mm-format SLR camera body, this adapter converts the PF-80ED into a high-power 1000mm F12.5 telephoto lens with a minimum focusing distance of approximately 5.8 meters (19 feet). Featuring a high-performance optical design with five multi-coated optical elements in four groups, it provides an outstanding color balance equivalent to that of high-quality 35mm-format interchangeable lenses. Even when the PF-80ED's eyepiece is replaced with the camera adapter while viewing, the original focusing is retained in most cases, thus allowing the user to retain the exact focusing point with little or no adjustment for photo shooting. This
adapter also allows the camera to retain its automatic exposure control function.

Specifications:
Model PF-CA35
Lens construction 5 elements 4 group
Focal length 1000 mm 1:12.5
Near focusing distance 5.8 m (19 ft)
PENTAX K mount
Weight 250g (8.8 oz.)
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