spiratone 500 mm mirror lens

Anyone fimiliar with the Spiratone line of Mirror Lenses? It seem that they
sold several different lens under their name at different times. I have a
Spiratone 500 mm "minitel - m (F8) taking a 72 mm filter size. All of the
other lenses sold by Spiratone seemed to have a 77mm filter size. Can
anyone supply information about this lens. BTW, it has a dedicated 2x
extender enabling it to become a 1000 mm lens (F11)

PCR

On Wed, 23 Jun 2004 01:09:09 GMT, "PCR" wrote:

Anyone fimiliar with the Spiratone line of Mirror Lenses? It seem that they
sold several different lens under their name at different times. I have a
Spiratone 500 mm "minitel - m (F8) taking a 72 mm filter size. All of the
other lenses sold by Spiratone seemed to have a 77mm filter size. Can
anyone supply information about this lens. BTW, it has a dedicated 2x
extender enabling it to become a 1000 mm lens (F11)

when the lens was made there were only a few lens makers in Japan and
two of them made lenses for many of the big manufacturers.

A company called KENKO made Spiratones stuff including the first zoom
lens on the market for 35mm. When Siratone closed its' door the line
was picked up by Cambridge Camera and sold under their CAMBRON line.

The info on the lens is so so.
500/8.0 Spiratone
Actual: 505/8.28, Distortion: 2.0%, Falloff: 0.4 stops at f/8
8
Resolution (lines/mm) at 1:41x
Center: Ex 44
Corner: Ex 36

Contrast (%) at 30 lines/mm:
Center: Med 42
Corner: Med 34

They say 44 lpmm is excellent but to me 80 lines is excellent.

THOM

PCR