Canon ef s 15 85mm f 3 5 5 6 is usm vs canon 17 85mm f 4 5 6?

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From Canon EF-S 15-85mm f/3.5-5.6 IS USM: Canon EF-S 15-85mm f/3.5-5.6 IS USM: A zoom lens by Canon for APS-C cameras, 15-85mm f/3.5-5.6. Specs - Maker: Canon - Focal length: 15-85mm (zoom) - Maximum aperture: f/3.5-5.6 (it gets darker as you zoom in) - Made for: APS-C sensors - Mounts: Canon EF - Stabilised: yes - Autofocus: yes What it frames like - On APS-C (Canon) (Canon EF): like 24-136mm on full frame; f/3.5-5.6 gives about the depth of field of f/5.6-9 there. ...

From Canon EF-S 17-85mm f/4-5.6 IS USM: Canon EF-S 17-85mm f/4-5.6 IS USM: A zoom lens by Canon for APS-C cameras, 17-85mm f/4-5.6.

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