Precisa was the name given to a series of cameras manufactured by the Beier company at Freital, near Dresden in Germany, since the late 1930s up to the mid 1950s.
There were three different basic models, with some variations derived from improvements and new technologies introduced during the production run. In all cases, they are dual format cameras: using 120 roll film, they can provide negatives 6x6 in size or, by using the accesory mask, 6x4.5 cm in size.
The Precisa I is a simple but solidly built camera. The front door opens to the side, and the lenses that this version can be found with are Xenar 75/2.8 on Compur-Rapid (pretty uncommon), or one out of two variants of the Rodenstock Trinar, a 75/3.5 on Prontor-II shutter or a 75/2.9 on Compur shutter.
The Precisa I was produced until the first years of WWII, and can be easily recognized because the film advance wheel is located in the bottom part of the camera's body. Some units of this Precisa I have the advance wheel painted black, and others chromed.
The first picture in this page shows the first evolution of that initial model, the Precisa II, first version made during the second half of the 1940s. The second version of this evolution has a full top cover housing the direct viewfinder, and was made in the 50s.
The top cover also houses the film advance wheel and the release button, as well as the door aperture button for deploying lens and shutter and extend the bellows. The second version includes a mask for the optical direct viewfinder so that composition can be made with the negative size in mind. This model is usually fitted with a Ludwig Meritar 75/3.5 lens on Binor or Junior shutters.
The Beier Precisa IIa or Mess-Precisa was introduced in 1956, and is shown in the second picture. The main improvement over the Precisa II is the addition of a non-coupled rangefinder to the optical viewfinder under the top cover. Distance measurements can be readen from a small window also located in the top cover, and then transferred manually to the front element of the lens. Distances readen vary between 1 meter to infinity. It is an uncommon camera, even despite it seems that it should not have been highly priced originally.
The lens mounted on this third evolution can be either Ludwig Meritar 75/3.5 or Meyer Trioplan 75/3.5 on Tempor or Junior shutters. The release button is also on the top of the camera, near the rangefinder. Two ruby windows in the back door allow shooting, in conjunction with the internal mask, negatives of 6x6 or 6x4.5 in size and position the frame accordingly. The combined viewfinder-rangefinder has a sliding button for positioning a composition mask.