Abbreviated History of The TLR – Twin Lens Reflex.

The exact history of the twin lens camera is frequently a shade obscure. However, here is a few of the highlights to show how the idea evolved.

Double-lens cameras were around from about 1870, when someone realised that having a second lens alongside the taking lens meant that one could focus without having to keep swapping a ground glass screen for the plate afterwards, making the time delay in actually taking the shot rather less. This sort of approach was still used as late as the nineteen-sixties. Where the TLR came into its own was with the idea of using a reflex mirror to allow viewing from above, thus allowing the camera to be held much more steadily if handheld.

The same principle of course applied to the SLR, but early SLRs caused delays and inconvenience through the need to move the mirror out of the focal plane to allow light to the plate behind it. When this process was automated, the movement of the mirror could cause shake in the camera and blur the shot.

The text extract bellow is from Edward Holmes’ An Age Of Cameras (1978), which is a prime source from early TLRs. George Matthews Whipple was a scientist and Superintendent of the Royal Observatory at Kew. It seems the design concept was his – to build a mirror reflex camera for cloud photography. As far as I can divine, the idea was to use a camera with lenses pointing upwards, but be able to compose the picture whilst looking horizontally. It seems this camera also used geared linking to synchronise the lenses.

Holmes implies the London Stereoscopic Co’s “Carlton” model, was the first off-the-shelf TLR from 1885. Interestingly, McKeown dates it from “c1895”, a significant difference at a time of rapid camera evolution.
However, it seems the Carlton was produced for an extended period with a number of variants (differing front cover/lenses, etc.), so perhaps both are right.
With some research, it seems probable London Stereoscopic never made cameras, but bought in from other sources. The two cameras below are other TLRs it sold – The Artist Hand Camera (left) was a rebadged French Kinegraphe (c1889) and the Artist Reflex (right) an evolved model from around 1910. All these cameras used plates of various sizes.

There were a number of other types of TLR marketed between about 1890 and 1910, but they were gradually overtaken as more effective SLRs became available and cured the problem of parallax which bedevilled the TLR. The ability to see and compose the subject exactly in the taking lens outweighed the disadvantage of the moving mirror as SLR mechanisms improved.

Then came the Rolleiflex…This is not the place for a proper Rollei history; that has been done at great length and detail by others more expert than I about the story. For those wanting detail, I’d refer you to the Global Rollei Club’s excellent site or to Ian Parker’s various books. Suffice it to say that many people believe that Reinhold Heidecke, 50% of the Franke & Heidecke partnership which grew into Rollei, invented the TLR. As You have read above – not so! Even Ian Parker, says in the Introduction to his 1993 Complete Rollei Collector’s Guide that “the original idea of the TLR was born in 1916 … 1927 the first prototype was completed … 1929 the first Rolleiflex TLR went into production”.

Clearly Heidecke didn’t invent the TLR, and as a long-time professional camera designer he must have known of earlier large-format designs. What apparently sparked his interest in reviving the concept was his realisation in the Great War trenches that photography over the parapet was an extremely hazardous business with enemy snipers on watch. His idea of an upside-down TLR of fairly compact dimensions, which could be held above one’s head like a periscope on a pole with remote shutter trigger, was not realised in commercial terms until after he and Paul Franke had been in business together for seven years – mainly making stereo cameras.

Source.