Specifications:

Brand Canon
Focal Length 3.9mm
Maximum Aperture f/3.5
Lens Mount Canon RF
Lens Format Coverage Full-Frame
Focus Type Autofocus
Image Stabilization No
Filter Size Gel Filter (Rear)
Maximum Aperture f/3.5
Minimum Aperture f/16
Lens Mount Canon RF
Lens Format Coverage Full-Frame
Angle of View 144°
Minimum Focus Distance 7.9″ / 200.7 mm
Maximum Magnification 0.03x
Optical Design 11 Elements in 8 Groups
Diaphragm Blades 7
Focus Type Autofocus
Image Stabilization No
Filter Size Gel Filter (Rear)
Dimensions (ø x L) 4.4 x 2.1″ / 11.2 x 5.3 cm
Weight 10.2 oz / 289 g
Package Weight 1.42 lb
Box Dimensions (LxWxH) 8.6 x 6.6 x 6.1″

Features:

Driving the RF-S 3.9mm f/3.5 STM Dual Fisheye is a gear-type stepping motor (STM) with a dual-lens autofocus mechanism, which drives the left and right lenses in unison.

This makes autofocus as simple to operate as it is with an ordinary lens. The electronic focusing/control ring and the left-right focus difference adjustment switch enhance operation by allowing adjustment of the left-right focus differential.

Autofocus operates only on subjects within the image circle of the left lens. Additionally, Servo AF is not available. Before shooting a movie, users must adjust the focus to One-Shot AF or manual focus.

The RF mount and the folded optical design allow for a compactl lens design that’s easy to use in tight spaces. Weighing just 10.2oz, this dual fisheye lens conveniently fits in most bags and is perfect for travel.

Ghosting and reflections are noticeably reduced by Canon’s air sphere lens coating. During challenging lighting conditions, such as backlit scenes, more contrast and uniform colors are present in your images.

Designed to support filters, 30.5mm screw-on filters can be attached to the rear of the lens, as well as a filter holder for cut gel and polyester filters.