• Aperture Range: f/4 to f/22
• Three Aspherical Elements
• Two ED and Four HR Elements
• Neutrino Coating
• Manual Focus Design with Focus Lock
• UV Fluorescent Engraved Markings
• Depth of Field and Focus Distance Scales
• Weather-Sealed Magnesium Alloy Housing
• Rounded Nine-Blade Diaphragm

 Beyond its optical assets, this 11mm f/4 lens also sports a manual focus design for fine-tuned control, and incorporates a unique positive focus lock to secure the focusing position at any point for consistent, repeatable shooting. As the Blackstone version of this focal length, this lens is also distinguished by an aluminum and magnesium alloy exterior, engraved lens markings with fluorescent UV paint for high visibility, and extensive weather-sealing about the lens to permit working in harsh environments.

The Blackstone version of the 11mm f/4 lens features a durable aluminum and magnesium alloy housing and weather-resistant exterior along with inner seals, and an extra seal at the front element, to protect against dust and moisture intrusion. The metal exterior also distinguishes itself with an anti-scratch finish, and sports engraved focus distance and depth of field scales with fluorescent UV paint for high visibility when working in low-light conditions.

Ultra wide-angle prime designed for full-frame DSLRs, this lens can also be used on APS-C models.

Three aspherical, four high-refractive index, and two extra-low dispersion elements are featured within the optical design to limit both spherical and chromatic aberrations, as well as color fringing and distortion, for improved clarity, sharpness, and even illumination.

A Neutrino coating has been applied to limit lens flare and ghosting for improved contrast and color fidelity.

Manual focus designed is benefitted by a positive focus lock mechanism to secure your focus position at any point to limit unwanted shifting of focus.

A hard click stop indicates the infinity position on the focus ring for easy use in low-visibility conditions.

Large depth of field scale benefits using hyperfocal and pre-focus techniques.

Built-in petal-shaped lens hood blocks stray light in order to reduce lens flare, and also protects the front element of the lens.

Rear of the lens accepts 30 x 30mm cut gel filters.
Rounded nine-blade diaphragm contributes to smooth bokeh.

Focal Length     11mm
Maximum Aperture     f/4
Minimum Aperture     f/22
Format Compatibility     Full-Frame
Angle of View     126°
Minimum Focus Distance     10.83" / 27.5 cm
Optical Design     16 Elements in 10 Groups
Diaphragm Blades     9, Rounded
Focus Type     Manual Focus
Image Stabilization     None
Filter Size     Gel Filter (Rear)
Dimensions (DxL)     4.65 x 4.06" / 118 x 103 mm
Weight     1.7 lb / 790 g