The 24mm f/2.0 Carl Zeiss T* Wide-Angle Prime Lens from Sony is for full frame format D-SLR cameras, but when used with cameras with APS-C sized chips it has the 35mm equivalent of a 36mm focal length. The lens features the highly-regarded Carl Zeiss Distagon retro-focus lens configuration designed for wide-angle lenses. The ultra fast f/2 wide-open aperture along with the 9-blade circular diaphragm allows you to work in low light, and with a minimum focus of 7.6" the lens allows you to get in close to your subject. This lens is distinguished by its fast focus response and extremely quiet, smooth operation, thanks to its built-in SSM (Super Sonic wave Motor), and the focus mode switch allows you to quickly change between manual and autofocus. In keeping with traditional Carl Zeiss design, the all-metal lens barrel has been finished to a very high standard resulting in both high-quality performance and appearance.