Yes, the Samyang 35mm T1.5 VDSLR MK2 Cine Lens for Canon EF is fully compatible with the Canon EOS 5D Mark III.

🔧 Compatibility Details
Mount Type: The lens features a Canon EF mount, which is the same mount used by the EOS 5D Mark III. This ensures seamless physical and electronic compatibility between the lens and the camera body.

Sensor Coverage: Designed for full-frame sensors, the lens provides optimal image quality and field of view on the 5D Mark III, which also has a full-frame sensor.

Functionality: As a manual focus cine lens, it offers precise control over focus and aperture, making it ideal for video production and cinematic photography.

📷 Additional Features
T1.5 Aperture: The fast T1.5 aperture allows for excellent low-light performance and shallow depth of field, enhancing creative possibilities.

Cine Design: Equipped with industry-standard gear rings for focus and aperture, the lens is compatible with follow focus systems, facilitating smooth and accurate adjustments during filming.

Build Quality: The lens boasts a robust construction with weather sealing, ensuring durability and reliability in various shooting conditions.

In summary, the Samyang 35mm T1.5 VDSLR MK2 Cine Lens is an excellent match for the Canon EOS 5D Mark III, offering high-quality optics and professional-grade features suitable for both photography and videography.