The Professional's Source Since 1973
  • Help
Ask Our Experts800.952.1815
Hello, Log InAccount & Orders

Join Bild Expo 2025 - Presented by B&H

Video Chat with a Pro Video Expert - Live

Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (FUJIFILM X, Neutral Flares)

BH #SI20AF133XXN • MFR #20AF133X-XN
Print
Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (FUJIFILM X, Neutral Flares)
Key Features
  • 37mm Image Circle Covers S35 Sensors
  • Creates 2.35:1 Aspect Ratio in 16:9
  • Eye-Tracking Autofocus with STM Motor
  • T1.8-T22 Aperture
Combining the cinematic quality of 2.35:1 widescreen imagery with the convenience of subject-tracking autofocus, this Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens is a versatile, wide-angle lens designed specifically for FUJIFILM X-mount cameras with Super 35 sensors. With a 1.33x squeeze factor and T1.8 maximum aperture, the lens ensures exceptional low-light performance and allows for stunning subject isolation with its signature oval-shaped bokeh.
More Details
New Release
New Item - Coming Soon
Free Expedited Shipping
Protect Your Gear
Add a protection plan from $97.99
Ask an Expert
800.952.1815

Sirui Auto Focus 20mm T1.8 Anamorphic Cine Overview

Combining the cinematic quality of 2.35:1 widescreen imagery with the convenience of subject-tracking autofocus, this Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens is a versatile, wide-angle lens designed specifically for FUJIFILM X-mount cameras with Super 35 sensors. With a 1.33x squeeze factor and T1.8 maximum aperture, the lens ensures exceptional low-light performance and allows for stunning subject isolation with its signature oval-shaped bokeh.

Powered by a precision STM stepping motor, the Sirui 20mm delivers smooth, accurate, and quiet autofocus—a rare feature in anamorphic lenses. With eye-tracking capability and buttons for both focus mode and autofocus lock, the lens provides complete creative control. A female USB-C port enables firmware updates, ensuring lasting performance. Compact and lightweight, the lens fits advanced technology and visual quality into a form factor ideal for handheld, gimbal, and run-and-gun shooting, making it a powerful tool for independent creators and professional productions.

Anamorphic Aesthetic
  • 1.33x squeeze factor for 2.35:1 images with a 16:9 sensor
  • Unique oval bokeh enhances subject separation and depth
  • Horizontal field of view equivalent to a 22mm full-frame lens
  • Neutral lens flares for cinematic effect
Optical Performance
  • 37mm image circle covers Super 35 sensors or full-frame with vignette
  • T1.8 to T22 aperture for low-light performance and depth of field control
  • 15.7" minimum focus distance for close-up shots
  • Aspherical lens element minimizes chromatic aberration
Advanced Autofocus
  • STM stepping motor for smooth, silent autofocus
  • Eye-tracking autofocus for reliability during movement
  • AF/MF switch to toggle between autofocus and manual focus
  • AF-lock button to hold focus or recall custom focus settings
Practical Design
  • Uniform gear positioning with Sirui 40mm AF Anamorphic Lens
  • Compact (3.8" long) and lightweight (1.1 lb)
  • 360° focus throw with standard gearing
Versatile Compatibility
  • Compatible with FUJIFILM X-mount cameras
  • Standard 77mm front filter thread
  • Update lens firmware via female UCB-C port

Sirui Auto Focus 20mm T1.8 Anamorphic Cine Specs

Key Specs
Focal Length
20mm
Maximum Aperture
T1.8
Lens Mount
FUJIFILM X
Lens Format Coverage
Super35/APS-C
Filter Thread
77 mm x 0.75
Image Stabilization
No
Electronic Communication
Yes
Maximum Aperture
T1.8
Minimum Aperture
T22
Lens Mount
FUJIFILM X
Interchangeable Mount
No
Horizontal Squeeze (Anamorphic)
1.33x
Flare Color
Neutral
Lens Format Coverage
Super35/APS-C
Image Circle
37.0 mm
Angle of View
Super 35
Horizontal: 85.6°
Vertical: 44.2°
Focus Scales
No
Optical Design
16 Elements in 12 Groups
Filter Thread
77 mm x 0.75
Minimum Focus Distance
1.3' / 0.4 m
Diaphragm Blades
11
Image Stabilization
No
Gear Standard
0.8 MOD
Gear Rotation
Focus: 360°
Electronic Communication
Yes
Camera Connection
1 x USB-C Firmware
Diameter
Focus Ring: 3.4" / 86.4 mm
Iris Ring: 3.1" / 80 mm
Length
3.59" / 91.25 mm
Weight
1.1 lb / 488.4 g
Packaging Info
Package Weight
2.38 lb
Box Dimensions (LxWxH)
7 x 5.7 x 5.6"

Sirui Auto Focus 20mm T1.8 Anamorphic Cine Reviews

See any errors on this page?
Whatever You Need, We've Got It