"The Irix 15mm Blackstone is a manual, super-wide-angle lens that allows you to stretch your creativity by expanding the viewing angle for a greater sense of space as well as opening up new perspectives for effects. It's the perfect lens for landscape, architectural and even interior photography. This versatile lens will adapt to every situation and the results are impressive, to say the least. The built-in hyperfocal distance scale gives you precise information about the depth of field for each aperture setting. The ergonomic focusing ring incorporates a convenient click-stop for the infinity setting. An innovative focus lock lets you easily set the focus anywhere on the scale and keep it there for consistently repeatable results and to help avoid focus drift. With a minimum focusing distance of 11.02"" (0.28m), you can get in close to your subjects for great wide-angle effects Irix has created the Blackstone lens with a weather-resistant exterior and inner seals, so you can use it in all weather conditions. It incorporates an extra seal at the front element for greater water resistance. Thanks to this construction, your Blackstone lens is protected from accidental water splashes, rain, snow, dust and other airborne particles. This makes it the perfect glass for photographers who need to work in all possible conditions. With its tough housing and engraved markings, it's also ideal for photographers who shoot in harsh environments.|Neutrino coating for minimal ghosting, chromatic aberration and flare, with maximum sharpness and contrast|UV reflective, engraved markings, ideal for night photography|15 elements in 11 groups for extremely high image quality|15 elements in 11 groups for extremely high image quality|Focus lock allowing you to maintain the chosen setting at any time|Weather sealed construction resists the elements for use in the harshest conditions|Additional weather seal at the front lens element|Hyperfocal distance scale for precise information about depth of field|Clearly-labeled infinity position for the focus ring with a noticeable ""click"" to make it easy to find, even in the dark|Minimum focus distance of 11.02"" (0.28m)|Ergonomic focus ring for faster focus|9 rounded diaphragm blades for a beautiful bokeh effect"