Housing a modern SLR camera allows you to see exact focus and composition, utilize auto focus, auto exposure, auto advance, precise metering, and have access to a large selection of lenses. Most people choose housed cameras due to their great macro capabilities. With just one macro lens, subjects can be composed in many different reproduction ratios without the use of framers. Zoom lenses allow you to shoot both macro and wide angle on the same dive. For all these benefits, there are a few trade-offs.
Housings are larger and require more time to assemble than amphibious cameras.
If you do not already own a SLR, then it can be more expensive. We recommend that you get to know your SLR very well before using it underwater. Practice on land will greatly improve your success. Choosing the right housing is an important decision. While you will find that they are similar in price, each differs in construction, control access, port design, and ergonomics.