Video Chat with a Pro Video Expert - Live

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

BH #SI20AF133XEN • MFR #20AF133X-EN
Print
Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Sony E, 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 Sony E-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
In Stock
No Store Display
$599.00
Calculate Shipping
Protect Your Gear
Add a protection plan from $87.99
Ask an Expert
212-444-6615

Sirui 20mm T1.8 Anamorphic AF 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 Sony E-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 both independent creators and professional productions.

Anamorphic Aesthetic
  • 1.33x squeeze factor for 2.35:1 images in 16:9 mode
  • Unique oval bokeh enhances subject separation and depth
  • Horizontal field of view equivalent to 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 reliable subject tracking
  • 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 Sony E-mount cameras
  • Standard 77mm front filter thread
  • Update lens firmware via female UCB-C port

Sirui 20mm T1.8 Anamorphic AF Specs

Key Specs
Focal Length
20mm
Maximum Aperture
T1.8
Lens Mount
Sony E
Lens Format Coverage
Super35/APS-C (37 mm Image Circle)
Filter Thread
77 mm x 0.75
Image Stabilization
No
Electronic Communication
Yes
Focal Length
20mm
Maximum Aperture
T1.8
Minimum Aperture
T22
Lens Mount
Sony E
Horizontal Squeeze (Anamorphic)
1.33x
Flare Color
Neutral
Lens Format Coverage
Super35/APS-C (37 mm Image Circle)
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
Aperture/Iris Blades
11
Image Stabilization
No
Gear Standard
0.8 MOD
Gear Rotation
Focus: 360°
Electronic Communication
Yes
Camera Connection
USB-CFirmware
Diameter
Focus Ring: 3.4" / 86.4 mm
Iris Ring: 3.1" / 80 mm
Length
3.58" / 90.95 mm
Weight
1.1 lb / 489.3 g
Packaging Info
Package Weight
2.39 lb
Box Dimensions (LxWxH)
6.5 x 6.2 x 5.7"

Sirui 20mm T1.8 Anamorphic AF Reviews

Fun lens, great price

By Michael
Rated 5 out of 5
Date: 2026-01-10

Love the results of the Sirui 20mm, Anamorphic, Blue flare for MFT on my Lumix GH4. Hopefully, this lens will find a home on my next B&H Photo purchase- the LUMIX GH7!

Amazing lens

By Henry
Rated 5 out of 5
Date: 2025-08-11

Really a very practical lens and with the quality I expected

See any errors on this page?

Does this have a focus hold when using the AF?

Does this have a focus hold when using the AF?
Asked by: Sherman
Yes, the Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Sony E, Neutral Flares) does include a focus hold (AF-Lock) button.
Answered by: Chris H
Date published: 2025-06-20

Does it support Sony gyro stabilization?

Does it support Sony gyro stabilization?
Asked by: Gavin
Sirui does not specifically state that the Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Sony E, Neutral Flares) is compatible with any stabilization; however, any in-body image stabilization system should be compatible with any lens.
Answered by: Kenneth C
Date published: 2025-04-23

Is there any vignetting if you combine this lens ...

Is there any vignetting if you combine this lens with the Sirui 1.25x adapter?
Asked by: Kieran
You may experience some vignetting when using the Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Nikon Z, Neutral Flares) with the Sirui 1.25x adapter.
Answered by: Boyd H
Date published: 2025-05-19

Constant 1.33 squeeze factor?

Constant 1.33 squeeze factor?
Asked by: john
Yes, the Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Micro Four Thirds, Neutral Flares) has a constant 1.33x squeeze factor.
Answered by: Paige K
Date published: 2025-10-16

Is this a focus by wire lens or will it work with ...

Is this a focus by wire lens or will it work with the DJI Focus Pro lidar?
Asked by: Timon
The Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens is a focus by wire lens but it is linear and can be used with the DJI Focus Pro LiDAR.
Answered by: John W
Date published: 2025-03-18

Is this lens compatible with the Sirui 1.25x ...

Is this lens compatible with the Sirui 1.25x anamorphic adapter?
Asked by: Kieran
Yes, the Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Nikon Z, Neutral Flares) is compatible with the Sirui 1.25x Anamorphic Adapter.
Answered by: Jonathan S
Date published: 2025-04-22

Is the squeeze factor constant?

Is the squeeze factor constant?
Asked by: john
Yes, the squeeze factor of the Sirui 20mm T1.8 1.33x S35 AF Anamorphic Lens (Micro Four Thirds, Blue Flares) is constant.
Answered by: Elliot A
Date published: 2026-04-13

Can this lens be used in full frame mode with ...

Can this lens be used in full frame mode with vignetting on Nikon bodies?
Asked by: Joshua
Yes, the Sirui 20mm T1.8 1.33x Anamorphic Lens can be mounted on full-frame Nikon Z bodies, with vignetting.
Answered by: Nick Y
Date published: 2025-11-11
  • y_2026, m_6, d_30, h_8CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.46
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_10
  • loc_en_US, sid_1881945, prod, sort_[SortEntry(order=HAS_STAFF_ANSWERS, direction=DESCENDING)]
  • clientName_bhphotovideo
Whatever You Need, We've Got It