Sirui Astra Series 50/75/100mm T1.8 Full-frame AF Anamorphic Cine Lens Kit (L Mount, Blue Flare)

Anamorphic lenses allow you to capture a wider field of view (typically 2.35:1 aspect ratio) from a standard sensor format (like 16:9) by horizontally compressing the image. This results in a cinematic widescreen look with distinctive oval bokeh and horizontal lens flares.

T-stop (T1.8) measures the actual amount of light transmitted through the lens, which is more accurate for exposure than an f-stop. While related, T-stops are generally more precise for cine lenses, especially when comparing exposure between different lenses. T1.8 is a fast aperture suitable for low light.

While designed for full-frame, they can be used on crop sensor cameras. However, the effective focal length and field of view will be narrower due to the crop factor, and the full anamorphic effect might be altered depending on the specific sensor size and how you choose to frame your image.

The kit comes with either a blue flare or neutral flare version. You select the desired flare characteristic when purchasing the lens kit. It is not a switchable feature on the lens itself.

The minimum focus distances vary by focal length: 50mm is 0.5m (1.64 ft), 75mm is 0.6m (1.97 ft), and 100mm is 0.7m (2.30 ft).

The lenses feature built-in autofocus motors that communicate with compatible camera bodies (L, E, Z mounts). The camera's AF system controls focus, allowing for single-shot AF and continuous AF modes, depending on camera settings and firmware support.

Triple protection refers to the lens's construction being resistant to dust, dirt, and rain, making it more durable and reliable for shooting in challenging environmental conditions.

Ensure your camera's firmware is up to date, as this often improves AF performance with third-party lenses. Check that the AF/MF switch on the lens is set to AF. Try selecting a specific focus point on your subject.

Verify the lens is securely mounted to the camera. Ensure the lens is focused correctly on the subject using either autofocus or manual focus. Check that the aperture is not set too wide if edge-to-edge sharpness is critical, although T1.8 is inherently softer than stopped-down apertures.

Blue flares are typically produced by strong, direct light sources hitting the front element. Ensure there is a direct light source (like a lamp, sun, or hard light) at an angle that will create streaks. The intensity and direction of the light will affect the flare appearance.

Double-check that you have the correct mount version for your camera. Ensure the lens is fully seated and locked onto the camera mount. Try cleaning the electrical contacts on both the lens and the camera mount.