What is the sigma 30mm f 1 4 dc hsm art good for?

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From Sigma 30mm f/1.4 DC HSM Art: Sigma 30mm f/1.4 DC HSM Art: A prime lens by Sigma for APS-C cameras, 30mm f/1.4. Specs - Maker: Sigma - Focal length: 30mm (prime) - Maximum aperture: f/1.4 - Made for: APS-C sensors - Mounts: Canon EF, Nikon F, Pentax K - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Nikon F, Pentax K): like 45mm on full frame; f/1.4 gives about the depth of field of f/2.1 there. - On ...

From Sigma 18-35mm f/1.8 DC HSM Art: Sigma 18-35mm f/1.8 DC HSM Art: A zoom lens by Sigma for APS-C cameras, 18-35mm f/1.8.

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