Sigma 17-40mm F1.8 DC | Art 025 vs Tamron 11-20mm f/2.8 Di III-A RXD

Both are Canon RF lenses for APS-C. Here is what actually differs.

Sigma · 2025

Pick the Sigma 17-40mm F1.8 DC | Art 025 if

You need 1⅓ stops more light for low light or background blur (f/1.8 vs f/2.8)
You need more reach: 40mm vs 20mm at the long end
You care about the shape of out-of-focus highlights: 11 aperture blades vs 7
You prefer a newer design: released 2025 vs 2024

Pick the Tamron 11-20mm f/2.8 Di III-A RXD if

You want a wider view: 11mm vs 17mm at the wide end
You shoot close-ups: it focuses down to 0.15 m vs 0.28 m
You want bigger close-ups: 0.25× vs 0.21× maximum magnification

Spec differences

13 differences

Specifications that differ between the Sigma 17-40mm F1.8 DC | Art 025 and the Tamron 11-20mm f/2.8 Di III-A RXD
	Sigma 17-40mm F1.8 DC \| Art 025	Tamron 11-20mm f/2.8 Di III-A RXD
Brand	Sigma	Tamron
Type	Zoom	Wide Zoom
Focal length	17-40mm	11-20mm
Max aperture	f/1.8 1⅓ stops faster	f/2.8
Weight	560 g	not listed
Length	115.9 mm	not listed
Diameter	72.9 mm	73 mm
Min focus distance	0.28 m	0.15 m closer
Max magnification	0.21×	0.25× larger
Aperture blades	11 more blades	7
Optical design	17 elements / 11 groups	12 elements / 10 groups
Autofocus motor	not listed	RXD
Released	2025	2024

5 identical specs hidden: mount, format, filter thread, image stabilization, weather sealing. Show all

Mount: Canon RF both
Format: APS-C both
Filter thread: 67 mm both
Image stabilization: No both
Weather sealing: Yes both

Our notes

Sigma 17-40mm F1.8 DC | Art 025

The Sigma 17-40mm F1.8 DC | Art 025 is an APS-C fast wide-angle zoom lens covering 17-40mm at f/1.8 for Canon RF mount cameras, from the Sigma Art line. It covers wide angles for landscapes, interiors and architecture.

Our notes