35mm Camera
Of all the types of cameras, the 35mm camera, or small format camera at they are sometimes called, have been the camera of choice for many years. The idea for using 35mm film came as early as 1905 by Oskar Barnack, who was working for the Ernst Leitz Company, a manufacturer of microscopes.
The film, originally was used in the movie motion picture industry, has a format size of 24mm x 36mm. In 1914, a format was tried using the same 35mm camera film, but instead it was 18mm x 36mm, or half sizes. This design camera had 750 exposures, but it did not last. In 1913, Leitz came out with a prototype 35mm camera, which used the 24mm x 36mm format, and it immediately led to a revolution in the camera industry.
There are two basic types of 35mm camera. One is the range finder coupled camera and the other is the SLR, or single lens reflex camera. A twin lens, 35mm reflex design was tried, but did not last.
The range finder coupled camera is a relatively small camera, light in weight, quiet in operation, and available with a wide variety of lenses. The range finder is an optical device used as the view finder, and also for setting the lens to the proper distance to be in focus. When looking through the range finder, and out of focus, there will be two images. Rotating the lens will bring the images together, and the camera will now be in focus.
The main disadvantage of this camera is that when viewing a subject close up, there is a parallax error, and what is seen in the view finder is not exactly the image that will be on the film. Other cameras of this type became available, but without the range finder. The photographer then had to estimate the lens and set the distance. An accessory range finder could be used to set the distance on the lens
The second type of 35mm camera is the SLR, or single lens reflex. This design uses a mirror at the mirror at the rear of the lens, which reflects up to a ground glass for viewing. The viewing is done from the top of the camera. Other use a prism, and viewing can be done from the rear of the camera. The huge advantage is that what you see in the view finder is exactly what will be on the film. The disadvantage is that the mirror is now between the lens and the film.
When the picture is to be taken, the mirror has to be moved out of the way. This takes time, it does make a noise, and will cause a vibration. These problems, due to good design, have been resolved to keep the problems to a minimum. Weight is problem, as glass is heavy, but this can be counteracted by using lighter materials in the construction of the camera.
Since the first cameras became available, numerous improvements have been made in the design and construction. Many features have involved, such as electronic flash, auto focus and automatic exposure. Motor drives to advance the film, and rewind it when finished.
Note that the digital age is upon, cameras have made a radical change, but some of the basic ideas are still being used.
