Sigma 17-40mm f/1.8 DC 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

17-40mm f/1.8 DC

f/1.8

Full specs

Tamron · 2024

11-20mm f/2.8 Di III-A RXD

f/2.8RXD

Full specs

Pick the Sigma 17-40mm f/1.8 DC 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

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 f/1.8 DC and the Tamron 11-20mm f/2.8 Di III-A RXD
	Sigma 17-40mm f/1.8 DC	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
Diameter	not listed	73 mm
Filter thread	not listed	67 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
Weather sealing	not listed	Yes
Released	not listed	2024

3 identical specs hidden: mount, format, image stabilization. Show all

Mount: Canon RF both
Format: APS-C both
Image stabilization: No both

Our notes

Sigma 17-40mm f/1.8 DC

This 17-40mm f/1.8 APS-C fast wide-angle zoom lens from Sigma fits Canon RF mount cameras. It covers wide angles for landscapes, interiors and architecture.

Our notes