Sigma 18-50mm F2.8 DC DN C Lens - Sony E-Mount

The filter size is 55mm.

No, this lens does not have built-in image stabilization. It relies on the camera's in-body image stabilization (IBIS) if the camera has that feature.

This lens is compatible with Sony E-mount cameras with APS-C sensors.

The closest focusing distance is 0.121 meters (approximately 4.76 inches).

Yes, the fast and silent autofocus makes it well-suited for video recording.

DC DN indicates that this lens is designed for mirrorless cameras with APS-C sensors.

The lens is not fully weather-sealed, but it is built with durable materials that help protect it from dust and moisture.

The serial number is located on the lens barrel.

Ensure the lens is set to autofocus mode (AF) on the lens barrel and that the camera's autofocus settings are correctly configured. Clean the lens contacts on both the lens and camera.

Check the focus by manually focusing or using a different focus point. Ensure the aperture is set correctly (smaller apertures provide greater depth of field). Check for camera shake and use a faster shutter speed or a tripod.

Ensure the lens is properly mounted onto the camera body. Check the lens contacts for any dirt or damage. Try restarting the camera.

Vignetting can be reduced by using in-camera correction, if available, or by adjusting the aperture. Consider post-processing the images to correct vignetting.