Canonet Lens Design

[Huck Finn]

I'm interested in finding out what formula was used to design the 40/1.7 lens on my Canonet QL17. Does anyon have any idea? Or what source might provide such info? Or even a lens diagram? I've had no luck searching for any of this.

Thanks for the help!
Huck :)

[back alley]

40mm f/1.7 (6 elements in 4 groups)

that's it from the canon museum.

[Doug]

Hmmm... Sounds like a classic double-Gauss?

[Pherdinand]

Well. The front element is a single positive convex-concave.
The central element is a cemented doublet.
That's all i know:)

[Huck Finn]

Hmmm... Sounds like a classic double-Gauss?

Yes, Doug, that's what I found when I continued my research. I still haven't found a drawing, but I did find a reference, which indicates a classic double Gauss, which was the primary suspect all along. Pretty much what Pherd describes, which a mirror image on the other side of the shutter, I suspect.

Thanks, guys. :)

[Canon Junkie]

http://www.kyphoto.com/classics/repairmanuals.html

go there and get the schematics for the camera and lens... will give you the whole design

[Huck Finn]

Junkie, I can't tell much about the lens elements from that. I downloaded the repair manual, but too small & sketchy to tell much. Am I missing something. It is a great resource for other purposes, however. Thanks for the link!