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Sigma A 17-40mm F/1.8 DC Lens
For Canon RF Mount
Weatherproof - Seals protect from dust, humidity and light splashing.
Zoom Lens
Rectilinear are normal lenses that show straight lines as straight lines.
Thread size in milimeters for screw-on filters.67
Autofocus LensLens Description
The Sigma A 17-40mm F/1.8 DC is a wide to normal zoom designed for cameras with a APS-C (1.6X) sensor. This ultra-bright constant-aperture zoom covers a 17 to 40mm focal-range. It provides the same field of view as a 27.2-64mm lens on a Full-Frame camera.
This 2X zoom lens focuses down to 28cm from the imaging plane. The lens supports autofocus and features a switch to disengage AF for focusing manually. A built-in focus motor is used to set the focus-distance. It allowed Sigma to optimize the motor precisely for this lens in order to maximize performance.
The lens weighs 560g. Its body is weatherproof against adverse weather such as rain and snow. Seals in key areas prevent entry of water and dust.
This version of the lens has a Canon RF mount. It directly attaches and is fully compatible with all Canon RF mount cameras with APS-C (1.6X) sensors. Sigma also makes this lens for Fujifilm X, Leica L and Sony E mounts.
Focal-Range
Angle-Of-View
Maximum Aperture
Viewing Angle Range
Maximum Aperture
Weight
Sigma A 17-40mm F/1.8 DC Specifications
| Brand | Sigma | Model | A 17-40mm F/1.8 DC |
|---|---|---|---|
| Mount | Max FLM | 1.6X | |
| Focal Range | 17 - 40mm | View Angle | 75 - 37° |
| Max Aperture | F/1.8 | Min Aperture | F/16 |
| Min Focus | 28cm | Magnification | Unknown |
| Filter Size | 67mm | Aperture Blades | 11 |
| Size (D x L) | 73 x 116mm | Weight | 560g |
| Tilt | N / A | Shift | N / A |
| Stabilization | Protection | Weatherproof | |
| Zoom Drive | Mechanic | Focus Drive | AF with MF Switch |
| Zoom Mechanism | External | Focus Mechanism | Internal |
| Hood | Bayonet | Focus Motor | Internal |
| Perspective | Rectilinear | Introduced | 2025-06-17 |
| Features | Aperture Ring. Dual AF-L buttons. | ||
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Sigma 17-40mm F/1.8 Facts
Weatherproof - Seals protect from dust, humidity and light splashing.Zoom LensRectilinear are normal lenses that show straight lines as straight lines.Thread size in milimeters for screw-on filters.67Autofocus Lens| 17-40mm Focal-Range | F/1.8 Constant Aperture |
| 67mm Filter Thread | AF with MF Switch |
| Canon RF Mount | APS-C (1.6X) Coverage |
| 560g Lens Weight | 73 x 116mm (D x L) |
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