A housing protects your camera/monitor from external (scratches to lens and body and damage to buttons) and internal damage (damage to the hardware).
With the new advances in housing technology (vacuum system and moisture alarm) you will be warned if there is the tiniest breach in your housing and you will most likely be able to get it topside and save it before anything bad happens. A housing not only protects your camera from the elements but it is also a platform for designing your own rig and getting the best photos out of your dive. A housing lets you build onto it with trays to get a more stable shoot, add some arms for lights and get better quality photos, add a wet lens to capture all the details of even the smallest of sea creatures.
We here at Fotografit are always happy to help you tailor the best equipment for your personal needs. Feel free to contact us with your questions at our webpage fotografit.eu (chat with us) or on our mail firstname.lastname@example.org.