Editing Viewfinder (section)

== Twin-lens reflex viewfinders ==
[[Twin-lens reflex camera|Twin-lens reflex]] (TLR) cameras use a viewfinding lens with the same [[focal length]] as the camera lens, so it has the same field of view and [[focus (optics)|focus]] properties. With a mirror, of similar size to the film, held at 45°, it projects an upright image onto a focusing ground glass screen viewable from above. The camera can be then be held steady at waist level. Although the viewfinder lens was similar to the camera lens, the optical quality was less important and so the cost is reduced. TLR viewfinders do not have the interrupted viewing and [[shutter lag]] of the SLR type and so is preferred for dance photography.<ref>{{cite web|url=http://www.arcaimaging.com/Dance_Movement_Photography.doc|title=Dance Movement Photography (DOC format)|website=arcaimaging.com|access-date=10 April 2018}}</ref>  Reinhold Heidecke cited his experience with [[periscope]] focusing from the German trenches in 1916 as the inspiration for the [[Rolleiflex]] line in 1929.<ref>"Complete Collector's Guide to the Rollei TLR, Ian Parker, Hove Photo Books, Jersey, 1993</ref>  Some similar-looking cameras are actually simple box cameras with a [[#Waist_level_(reflecting)_viewfinders|waist-level]] viewfinder.