The Pictures above are merely examples, there are many brands and sizes of these three types of cameras. Pictured, Sealife DC1400, Olympus EPL1, and Nikon D610.
When it comes to shooting pictures underwater, there are three different (major) types of cameras that can be used. Technically, four, but two are similar, the only difference is one is digital while the other records a picture to film. Let me explain.
- Fully Automatic digital camera
- 4/3rds digital camera
- dSLR/SLR (This is the 3 or 4… but extremely similar)
Fully automatic digital camera configures all the settings needed to take a shot. It is also referred to as a point and shoot camera. You compose your photo, point and shoot, and you have your picture stored on your memory card in a jpeg format.
A 4/3rds digital camera is a mirrorless camera designed with interchanging lenses such as a dSLR/SLR but it was designed to be entirely digital. Because the cameras tend to be smaller than dSLR/SLR cameras, the sensor and lenses can be significantly smaller.
A dSLR is a digital SLR camera. SLR stands for single-lens reflex camera. A SLR camera tends to use a mirror/prism system that allows the photographer to view through the lens and see exactly what will be captured. The digital just allows for it to be captured on a memory card versus film.
Not every photographer will be well suited for all three types of underwater cameras, this is merely an example of the options available.