Offering a broad field of view and a bright design, the PFU RBMH 20mm f/1.8 ASPH from Viltrox is an ultra-wide prime lens for Sony E-mount mirrorless cameras. The wide-angle design and fast f/1.8 maximum aperture make it well suited to astrophotography use, as well as landscape, interior, and architectural shooting. Its optical design incorporates a series of aspherical and low dispersion elements, which reduce spherical and chromatic aberrations for sharp, well-corrected imagery with accurate colour rendering. An HD Nano multi-layer coating has also been applied to suppress flare and ghosting for improved contrast when working in strong lighting conditions. The lens has a manual focus design, which permits working with subjects as close as 25cm away, and its 14-blade diaphragm contributes to a pleasing bokeh quality. Additionally, it is constructed from brass for durability and smooth operation.

Ultra-wide prime is designed for full-frame Sony E-mount mirrorless cameras; however, it can also be used with APS-C models where it provides a 30mm equivalent focal length.
Bright f/1.8 maximum aperture suits working in difficult lighting conditions and also offers increased control over depth of field.
Four extra-low dispersion elements, one double-sided aspherical element, and one element made from highly transparent glass all contribute to reducing a variety of aberrations in order to produce a well-corrected image with accurate colour and high sharpness.
HD Nano multi-layer coating has been applied to individual elements to reduce flare and ghosting for improved contrast. Also, this coating is water-resistant to help protect the exposed surfaces from moisture.
Manual focus design, with a 148.5° focus throw, permits working with subjects as close as 25cm away.
Engraved focus distance and depth of field scales benefit working with prefocus and hyperfocal focusing techniques.
A 14-blade diaphragm contributes to a pleasing bokeh quality.
Brass lens barrel construction realizes a physically durable design that also affords smooth operation.
An included lens hood helps to prevent flare and also affords some protection to the bulbous front element. Additionally, a filter adapter ring is included for mounting 82mm screw-in filters.