If the camera has interchangeable backs you can change a film mid-roll so you could shoot colour and black & white within seconds of each other. This is also useful if you have several users using a camera - each could have there own film back. It s also good to record specific subjects on the same roll of film. For example you re out walking and you could take flowers on one and landscapes on the other. Many medium-format cameras have the option of changing format with different backs. You could, for example shoot 6x7cm, 6x4.5cm and 35mm from the same camera using three different backs. Polaroid backs are also available for many cameras. This means you could shoot a Polaroid print and instantly check lighting, composition or exposure and then replace with the conventional film.ephotozine
One of a system of detachable lenses of different characteristics, generally focal length variety, each of which fits a given camera body.
Some camera systems offer the ability to swap lenses at any time and offer a magnitude of lenses for any given situation. Most commonly found on single-lens reflex (SLR) cameras.
Many SLRs and medium-format cameras have interchangeable focusing screens. The benefit is that you can swap the standard split screen for a different pattern to suit the type of photography you are doing. The most common is a grid screen that has a grid of thin lines used to align horizontal and vertical points in the scene. This is a popular choice for architectural photographers and for copying. A plain screen is used for microscope and telescope work, and some prefer a fresnel for focusing with long telephoto lenses where the split screen version may black out.
– DSLR and mirrorless camera lenses can be removed, allowing the photographer to choose the best lens for a particular type of shot.
If the camera has interchangeable lenses you have more flexibility because the lens detaches from the camera allowing it to be replaced by a different one. Most 35mm SLR cameras and many medium-format cameras have interchangeable lenses.