Reflector (photography) - Wikipedia

The Gregorian telescope employs a concave secondary mirror that reflects the image back through a hole in the primary mirror.

Camera lucida - Wikipedia

Used Nikon Nikkormat FTn [Film] SLR w/50mm f2 Nikkor-H (F-mt) Lens

Reflector (photography) - Wikipedia

Reflections - Reflectors and Available Light Photography

Roseland observatory

Photography Reflectors: 7 BEST Things To Learn All About Them

File:Kew Riverside, Parabolic Reflector.jpg - Wikipedia

Parabolic aluminized reflector - Wikipedia

Rearview Mirror: Paul Kantner

File:Dual corner reflector UHF TV antenna.png - Wikipedia

Retroreflector - Wikipedia

Reflector (photography) - Wikipedia

File:PSM V74 D518 Steel building and 60 inch reflector.png - Wikipedia