The Sirui 50mm f/1.8 1.33x is an anamorphic lens from the Chinese manufacturer Sirui, designed for use on cameras with sensors up to APS-C size. Its primary function is to horizontally compress the recorded image by a factor of 1.33.
The lens is manufactured in a factory in China.
Anamorphic Properties of the Lens
Through the horizontal compression of the image by a factor of 1.33, the field of view is expanded horizontally by 33%. This corresponds to the horizontal angle of view of a 37.5mm lens on an APS-C camera. If a 16:9 format recording is digitally de-squeezed in post-production, the result is a widescreen format with an aspect ratio of 2.4:1.
The characteristic imaging features of the lens include an oval bokeh, created by the 10 aperture blades, as well as horizontal blue lens flares from direct light sources.
Optical Design and Mechanical Details
The optical construction of the lens consists of eleven lens elements in eight groups. Among these are glass elements from the German manufacturer Schott. The lenses are treated with a multi-layer nano-coating. The housing is made of aluminum, and the total weight of the lens is around 560 grams.
The lens has a fixed focal length of 50 millimeters. The maximum aperture is f/1.8, and the minimum is f/16. Focusing is done manually via a focus ring with a rotation angle of 143.6 degrees. The minimum focusing distance of the lens is 0.85 meters. On the front, it features a 67mm filter thread for attaching filters.
Compatibility of the Sirui 50mm f/1.8 1.33x
The Sirui 50mm f/1.8 1.33x is designed for camera systems with APS-C sensors and is offered with various mounts, including Sony E-Mount (NEX), Fujifilm X-Mount, Canon RF-Mount, Leica L-Mount, and Micro Four Thirds (MFT). In addition to this model, Sirui offers other anamorphic lenses with different focal lengths for APS-C and also for full-frame cameras.
Technical datasheet
| Attribute | Specification |
|---|---|
| Widest aperture | f/1.8 |
| Smallest aperture | f/16 |
| Minimum focus distance | 85 cm |
| Number of elements | 11 |
| Number of groups | 8 |
| Number of aperture blades | 10 |
| Filter thread | 67 mm |
| Weight | 560 g |
| Company name of the brand | GUANGDONG SIRUI OPTICAL CO., LTD. |
| Country of production | China |
| Price orientation | 700 US-Dollar |





