The SIRUI Astra 50 mm T1.8 brings autofocus to full-frame anamorphic filmmaking, pairing a consistent 1.33x squeeze with a fast cinema aperture. Its perspective suits dialogue, documentary scenes and natural-width compositions, and this L-Mount version has a blue streak flare character.
Anamorphic framing and flare character
The constant 1.33x squeeze records a wider horizontal perspective than a spherical lens of the same focal length. When the footage is de-squeezed in post-production, it takes on an approximately 2.35:1 widescreen character from 16:9 capture, together with the elongated bokeh and visual depth associated with anamorphic optics.
Autofocus and practical cine handling
The T1.8 aperture is useful for controlled background blur and available-light scenes. An STM-driven autofocus system and AF/MF switch make the lens practical for independent productions, while cine-oriented focus and aperture controls allow more deliberate operation when needed. The blue flare version is designed for L-Mount; minimum focus is 0.50 m.
SIRUI lists an 18-element, 14-group optical design for the 50 mm. Its balanced perspective is useful when a scene needs both a recognisable environment and the wider anamorphic character, rather than a tightly compressed telephoto composition.
Key features
- Full-frame coverage and constant 1.33x anamorphic squeeze
- 50 mm focal length for storytelling and detailed framing
- Fast T1.8 maximum aperture
- STM autofocus with AF/MF switch
- 67 mm filter thread and common cine gear positions
- Minimum focusing distance: 0.50 m
- Blue flare rendering
- L-Mount
What's in the box
- Astra 50 mm T1.8 1.33x anamorphic cine lens
- Front and rear lens caps
- Manufacturer warranty card
