Sigma 17-40mm F1.8 DC | Art 025 vs Tamron 16-50mm f/2.8 A

Both are Canon RF zoom lenses. 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 care about the shape of out-of-focus highlights: 11 aperture blades vs 7

Pick the Tamron 16-50mm f/2.8 A if

You want the lighter lens to carry: 255 g lighter (305 g vs 560 g)
You want a wider view: 16mm vs 17mm at the wide end
You need more reach: 50mm vs 40mm at the long end
You shoot close-ups: it focuses down to 0.15 m vs 0.28 m
You prefer a newer design: released 2026 vs 2025

Spec differences

13 differences

Specifications that differ between the Sigma 17-40mm F1.8 DC | Art 025 and the Tamron 16-50mm f/2.8 A
	Sigma 17-40mm F1.8 DC \| Art 025	Tamron 16-50mm f/2.8 A
Brand	Sigma	Tamron
Format	APS-C	not listed
Focal length	17-40mm	16-50mm
Max aperture	f/1.8 1⅓ stops faster	f/2.8
Weight	560 g	305 g lighter
Length	115.9 mm	not listed
Diameter	72.9 mm	not listed
Filter thread	67 mm	55 mm
Min focus distance	0.28 m	0.15 m closer
Max magnification	0.21×	0.22× larger
Aperture blades	11 more blades	7
Optical design	17 elements / 11 groups	14 elements / 10 groups
Released	2025	2026

4 identical specs hidden: mount, type, image stabilization, weather sealing. Show all

Mount: Canon RF both
Type: Zoom 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