Digital photoshoot of a flying oldtimer

Prior to the development of SLR, all cameras with viewfinders had two optical light paths: one path through the lens to the film, and another path positioned above ( TLR or twin- lense reflex) or to the side ( rangefinder). Because the viewfinder and the film lens cannot share the same optical path, the viewing lens is aimed to intersect with the film lens at a fixed point somewhere in front of the camera. This is not problematic for pictures taken at a middle or longer distance but parallax causes framing errors in close-up shots. Moreover, focusing the lens of a non-reflex camera when it is opened to wider apertures (such as in low light or while using low-speed film) is not easy.