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Combining the cinematic quality of 2.35:1 widescreen imagery with convenient subject-tracking autofocus, this Sirui 40mm T1.8 1.33x S35 AF Anamorphic Lens is a versatile lens designed for Super 35 Leica L-mount cameras. It ensures exceptional low-light performance and oval-shaped bokeh with a 1.33x squeeze factor.
Compact Design with Autofocus
Powered by a precision STM stepping motor, the Sirui 40mm delivers smooth, accurate, and quiet autofocus, a feature rarely found in anamorphic lenses. With eye-tracking capability and buttons for both focus mode and autofocus lock, the lens provides complete creative control. It incorporates a USB-C port for 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 with Neutral Flares
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.
Horizontal neutral streak effects create a warmer anamorphic look that adapts to your light source.
Optical Performance
A 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.
23.6" 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 and lightweight design.
360° focus throw with standard 0.8 MOD gearing.
Versatile Compatibility
Compatible with Leica L-mount cameras
Standard 77mm front filter thread.
Update lens firmware via the UCB-C port.
Sirui 40mm T1.8 Anamorphic AF Specs
Key Specs
Focal Length
40mm
Maximum Aperture
T1.8
Lens Mount
L-Mount
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
40mm
Maximum Aperture
T1.8
Minimum Aperture
T22
Lens Mount
L-Mount
Lens Format Coverage
Super35/APS-C (37 mm Image Circle)
Angle of View
Super 35 Horizontal: 55° Vertical: 25.4°
Optical Design
16 Elements in 12 Groups
Filter Thread
77 mm x 0.75
Minimum Focus Distance
1.97' / 60 cm
Aperture/Iris Blades
11
Image Stabilization
No
Lens Mounting
No
Gear Standard
Focus, Iris: 0.8 MOD
Gear Rotation
Focus: 360°
Electronic Communication
Yes
Camera Connection
Flat Contacts (EXIF) Data
Diameter
Front: 3.1" / 80 mm
Length
Not Specified by Manufacturer
Weight
1.4 lb / 614 g
Packaging Info
Package Weight
2.975 lb
Box Dimensions (LxWxH)
8.5 x 6.3 x 5.9"
Sirui 40mm T1.8 Anamorphic AF Reviews
Poor build quality
By Mike
Rated 2 out of 5
Date: 2026-03-29
The back of the lens from the aperture ring to the mount became loose, so the lens can no longer mount solidly to the camera. This also causes the plane of focus to shift as the lens wiggles.
The autofocus works well enough (except for the shifting plane of focus). The image quality is decent, especially for an anamorphic lens in this price range. I would have rated it 4-stars if not for the poor build quality.
Good not great
By Robert
Rated 4 out of 5
Date: 2025-05-12
I use this on a sony FX30. This is one of the first anamorphic AF systems- I am sure it ill get better but it is lacking now. AF does not lock on the subject- it will hunt around even with a static subject.
I found myself shooting in MF - kind of defeats the reason I bought this lens.
Image quality is good enough.
See any errors on this page?
When mounted on a Fujifilm X body are you be able ...
When mounted on a Fujifilm X body are you be able to see both "Body" and "Lens" firmware versions?
Asked by: Gary
Only native Fuji lenses will display their firmware version in the camera menu. Third-party lenses, such as the Sirui 40mm T1.8 1.33x S35 AF Anamorphic Lens (FUJIFILM X, Neutral Flares), will not show firmware information in the camera’s menu.
Answered by: Chris H
Date published: 2025-07-05
On an APS-C camera, such as the Sony FX30, what ...
On an APS-C camera, such as the Sony FX30, what would be the equivalent focal length of this 40mm Sirui Anamorphic Lens?
Asked by: Craig
The Sirui 40 mm T1.8 1.33x S35 AF Anamorphic Lens (Sony E, Neutral Flares) would have a 60 mm view on the APS-C sensor of the Sony FX30.
Answered by: Chris H
Date published: 2025-09-01
I am not seeing Nikon Full Frame cameras showing ...
I am not seeing Nikon Full Frame cameras showing up as "compatible" to this lens. I have cameras like Z6III. Why is that?
Asked by: Taka
The Sirui 40mm T1.8 1.33x S35 AF Anamorphic Lens (Sony E, Blue Flares) is an S35 lens and will not support a full-frame camera. However, most cameras have APS-C or S35 modes, and if you use your camera in crop sensor mode, the lens will work. Also, make sure to purchase the Z-mount lens model. See below:
Sirui 40mm T1.8 1.33x S35 AF Anamorphic Lens (Nikon Z, Blue Flares), BH # SI40AF133XZB
Answered by: Elliot A
Date published: 2025-11-03
Can this lens (in any of its formats) be adapted ...
Can this lens (in any of its formats) be adapted to a Canon RF camera?
Asked by: Craig
No, unfortunately, the Sirui 40 mm T1.8 1.33x S35 AF Anamorphic Lens in Leica L, Sony E, Nikon Z, FUJIFILM X, or Micro Four Thirds does not adapt to or have an adapter for connecting to an RF-mount camera.
Answered by: Elliot
Date published: 2025-06-12
The angle of view specs for the MFT version are ...
The angle of view specs for the MFT version are the same as the E-mount version. Is the MFT crop factor taken into account here?
Asked by: David
When using the Sirui 40mm T1.8 1.33x S35 AF Anamorphic Lens (Micro Four Thirds, Neutral Flares) and all other lenses, the focal length of a lens does not change when used on a different system; it is the field of view compared to a full frame that changes. Crop factor compared to 35mm equivalent is only relevant when comparing to full frame.
Answered by: Elliot
Date published: 2025-09-01
Is this compatible with the Z-Mount Red Komodo X?
Is this compatible with the Z-Mount Red Komodo X?
Asked by: Daniel
The actual answer is "not yet" - Sirui has not released the appropriate firmware for this to work on the Komodo-X Z-mount (their response to me). The lens will mount, but will have no power and will not be recognized by the KX. Without power, the iris is stuck at f/22, cannot be adjusted, and the lens cannot even be manually focused.
Answered by: Ron
Date published: 2025-07-12
Can you change the mount like you can do on some ...
Can you change the mount like you can do on some of the Siri?
Asked by: Paul
The mount of the Sirui 40mm T1.8 1.33x S35 AF Anamorphic Lens (Leica L, Blue Flares) cannot be changed or swapped.
