It'll collect dirt. A lot of rocket starts have been filmed and photographed using mirrors. A small silvermirror is much much cheaper than most lenses and doe

It'll collect dirt. A lot of rocket starts have been filmed and photographed using mirrors. A small silvermirror is much much cheaper than most lenses and doesn't change picture quality much (if the mirror glass is good). Mirrors can also be easier cleaned; in the simplest model you pour acid over the backside to dissolve the silver then run the silver-drenched acid over a mirror while neutralizing it (of course the actual process is much more complicated.