Mirrors of Keck Observatory
<a href="//commons.wikimedia.org/wiki/User:Phoenix7777" title="User:Phoenix7777">Phoenix7777</a>
CC BY-SA 4.0
This file was derived from: <a href="//commons.wikimedia.org/wiki/File:Comparison_optical_telescope_primary_mirrors.svg" title="File:Comparison optical telescope primary mirrors.svg">Comparison optical telescope primary mirrors.svg</a> <i>by</i> <a href="//commons.wikimedia.org/wiki/User:Cmglee" title="User:Cmglee">Cmglee</a><br>