Two Aspherical Elements Aperture Range: f/2 to f/22 Z-Mount Lens/FX Format Three Extra-Low Dispersion Elements The Laowa 15mm f/2 FE Zero-D Lens from Venus Optics is a rectilinear lens with a sophisticated optical design to effectively limit distortion. The bright f/2 maximum aperture makes this lens especially useful for astrophotography and low-light use, and when paired with the 5.9" minimum focusing distance, distinct shallow depth of field imagery can also be produced. The optical construction includes three extra-low dispersion elements and two aspherical elements to control both chromatic and spherical aberrations for greater sharpness, clarity, and reduced color fringing. A Frog Eye Coating has been applied, too, to repel dust and moisture from the front element of the lens to benefit working in trying environmental conditions. Additionally, the manual aperture ring can be de-clicked for smooth, silent aperture changes to suit video applications, and the front of the lens is threaded to accept 72mm screw-in filters. Ultra wide-angle prime is designed for FX-format Nikon Z-mount mirrorless cameras. Relatively fast f/2 maximum aperture benefits astrophotography and low-light shooting applications. Rectilinear design renders subjects with minimal distortion in order to suit landscape and architectural applications. Three extra-low dispersion elements reduce chromatic aberrations and color fringing for increased clarity and color neutrality. Two aspherical elements are also featured to limit spherical aberrations for improved sharpness. A Frog Eye Coating has been applied to repel both dust and moisture for added protection when working in inclement conditions. Manual focus design permits working with subjects as close as 5.9" away with a maximum magnification ratio of 1:4. The manual aperture ring can be mechanically 'de-clicked' for smooth, silent rotation throughout the aperture range; making it ideal for video applications.