Compare lenses

Canon EF-S 15-85mm f/3.5-5.6 IS USM vs Canon EF-S 17-85mm f/4-5.6 IS USM

The Canon EF-S 15-85mm f/3.5-5.6 IS USM and the Canon EF-S 17-85mm f/4-5.6 IS USM side by side, computed from this guide's catalogue.

Which to pick

Pick the Canon EF-S 15-85mm f/3.5-5.6 IS USM if you want a brighter f/3.5 (0.4 stops more light), for dim light and softer backgrounds and a wider view (from 22mm equivalent). On these specs the Canon EF-S 17-85mm f/4-5.6 IS USM has no clear advantage: choose it if the price, the handling or a lens you own decides it.

Still torn? Ask the guide about the Canon EF-S 15-85mm f/3.5-5.6 IS USM and the Canon EF-S 17-85mm f/4-5.6 IS USM

Specs side by side

Rows that differ are in full colour; the better value is marked where one is better by any measure.
Spec	Canon EF-S 15-85mm f/3.5-5.6 IS USM	Canon EF-S 17-85mm f/4-5.6 IS USM
Maker	Canon	Canon
Focal length	15-85mm (zoom)	17-85mm (zoom)
Full-frame equivalent	22-128mm on APS-C	26-128mm on APS-C
Maximum aperture	f/3.5-5.6brighter	f/4-5.6
Made for	APS-C	APS-C
Mounts	Canon EF	Canon EF
Stabilised	yes	yes
Autofocus	yes	yes
Zoom range	5.7×more range	5.0×
Cameras it fits	14 in this guide	14 in this guide

Focal range, in full-frame terms

Canon EF-S 15-85mm f/3.5-5.6 IS USM: 15-85mm on APS-C, like 22-128mm.

Canon EF-S 17-85mm f/4-5.6 IS USM: 17-85mm on APS-C, like 26-128mm.

Aperture

Canon EF-S 15-85mm f/3.5-5.6 IS USM: f/3.5 wide open.

Canon EF-S 17-85mm f/4-5.6 IS USM: f/4 wide open.

Each opening drawn to scale against f/1.4: a smaller f-number lets in more light and blurs the background more.

Field of view

How wide each sees, at each end, on the sensor it was made for.

Cameras they fit

14 cameras in this guide take both, so either works on the same body.