Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare)

Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare) Key Features:

• S35 auto focus anamorphic lens for L-mount cameras
• 1.33x constant squeeze ratio for a cinematic look
• Horizontal field of view equivalent to a 22mm full-frame lens
• Fast T1.8 aperture for sharp images even in low light
• Lemon-shaped oval bokeh for a unique look
• Advanced optical design of 16 elements in 12 groups
• Includes 1 aspherical and 5 cylindrical lens elements
• 0.4m minimum focus distance for immersive shooting
• Rapid autofocus and precise eye-tracking support
• STM stepping motor provides fast focus suitable for video
• Supports autofocus and manual focus to suit your needs
• Neutral flare ideal for natural and warm shooting
• Consistent size, shape, and design with lenses in the set
• Compact size for use with gimbals or professional rigs

Cinematic widescreen in a compact form

The Sirui 20mm T1.8 1.33x S35 AF Lens delivers a widescreen look with its constant 1.33x squeeze ratio, producing a 2.35:1 aspect ratio in 16:9 recording modes. With a 20mm focal length and a horizontal view equivalent to 22mm on a full-frame lens, it captures expansive views ideal for landscapes, interiors, or astrophotography while maintaining the signature anamorphic depth. Despite its optical performance, it remains compact, at just 88.35mm in length and 494.5g, making it highly practical for gimbal or handheld work.

Advanced optical design for high-quality imaging

The Sirui 20mm T1.8 1.33X S35 AF lens is designed to produce high-quality images and videos. With a 16-element, 12-group construction, it integrates an aspherical lens to minimise weight and chromatic aberration, alongside five cylindrical elements that control light distribution and maintain accurate anamorphic rendering. With an 11-blade aperture and a fast T1.8 maximum aperture, the lens produces sharp subjects, natural background separation, and elliptical bokeh. A 0.4m minimum focus distance further enhances creative framing, enabling immersive shots with strong depth.

Precision autofocus with professional control

Equipped with an STM stepping motor, the Sirui 20mm T1.8 1.33X S35 AF lens achieves rapid and accurate autofocus, supporting eye-tracking for enhanced stability even in fast-moving environments. For greater flexibility, AF and MF modes are switchable via dedicated controls. An AFL button offers auto-focus locking or custom settings, and an on/off switch for stepless aperture control suits your shooting preferences. This ensures both filmmakers and photographers can rely on precise subject tracking while retaining manual focus precision when required.

Designed for consistency across productions

Sirui’s design ensures operational uniformity across the lens set, with standardised 77mm filter threads, aligned gear positions, and consistent colour tones. This allows for quick changes without the need to adjust accessories, whether working with gimbals or matte boxes. The lens also features electronic contacts for EXIF transfer, firmware updates via Type-C, and a robust aluminium alloy body, providing users with reliable performance and practical integration with modern camera systems.

What’s in the box?

• 1 x Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare)
• 1 x Pouch
• 1 x Strap
• 1 x Front Lens Cap
• 1 x Back Lens Cap
• 1 x Warranty Card

FAQs:

Does the Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare) cover full-frame sensors?

The Sirui 20mm T1.8 1.33x AF lens is designed for S35/APS-C format coverage with a maximum image circle of 37mm. It can be mounted on full-frame cameras, though some vignetting may occur. This makes it best suited for S35 systems but still adaptable for wider sensor formats if required.

What is the focus throw of the Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare), and how does it benefit users?

This lens offers a 360° focus throw, providing precise manual control over focus adjustments. The extended rotation is particularly useful for pulling focus in cinematic applications where accuracy is critical. It allows operators to achieve smooth and controlled focus transitions across the entire range.

What are the magnification ratios of the Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare)?

The maximum magnification is measured at 1:15.4 vertically and 1:20.6 horizontally. While not designed as a macro lens, these ratios allow for close framing of subjects without distortion. When combined with the 0.4m minimum focus distance, it provides strong creative control for detailed shots.

How does the flare option affect image output?

This version of the lens features a neutral flare, designed to adapt naturally to different light sources without imposing a strong colour cast. It produces warm and realistic highlights that are well-suited for commercial and portrait work. This makes it a strong choice for those seeking cinematic character without stylised blue streaks.

Is the Sirui 20mm T1.8 1.33X S35 AF Lens (L mount, Neutral Flare) compatible with filters?

The Sirui 20mm T1.8 1.33X S35 AF lens has a 77mm threaded filter size. This allows straightforward attachment of ND filters or other accessories without special adaptors. The consistent size across the series also ensures uniformity when swapping between lenses in multi-lens productions.