If you are talking about converter lenses (telephoto and wide angle), there are a few that will fit the Olympus C-770.

http://raynox.co.jp/english/digital/c750uz/index.htm

You will have to use the Raynox adapter tube instead of the Olympus CLA-4 tube.

There are probable others, but I could not find them.

Interestingly, the Olympus TCON-17 and WCON-07 lenses are very popular and adapted to other brand of cameras.

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