I use cameras and lenses Nikon . I consider that it is very good choice for the professional.
For example NASA Orders D3S Digital SLR Cameras and Interchangeable Lenses from Nikon.
The D3S digital SLR cameras and AF-S NIKKOR 14-24mm f/2.8G ED lenses ordered by NASA will be carried on the Space Shuttle and used to photograph activities at the International Space Station (ISS) in the future.
No special modifications will be made to these products. They will be the same products available to end-users, confirming the incredible versatility of the D3S. This equipment will be used along with the Nikon D2XS digital SLR cameras, NIKKOR lenses, and Nikon Speedlights already in use at the International Space Station.
Nikon has spent many years contributing to NASA's study of space through the development and manufacture of advanced and extremely durable cameras as well as of NIKKOR lenses that make the most of Nikon’s optical technologies, and of which production has recently reached fifty million units. To date, NASA has captured more than 700,000 images using Nikon equipment carried into space. Space, however, is not the only extreme environment in which Nikon equipment is used. Nikon also provides official observation equipment used in exploring the Antarctic. Nikon equipment contributes to observation and research of these little explored regions with durability, reliability and technical capabilities that stand up to even the most severe environments.