Is the pentax hd d fa 70 210mm f 4 ed sdm wr worth it?

Here is what the site says about that.

From Pentax HD D FA 70-210mm f/4 ED SDM WR: Pentax HD D FA 70-210mm f/4 ED SDM WR: A zoom lens by Pentax for Full frame cameras, 70-210mm f/4. A lighter alternative to the f/2.8 telephoto zoom. Specs - Maker: Pentax - Focal length: 70-210mm (zoom) - Maximum aperture: f/4 - Made for: Full frame sensors - Mounts: Pentax K - Stabilised: no - Autofocus: yes What it frames like - On full frame (Pentax K): as marked, 70-210mm. - On APS-C (Pentax K): like 105-315mm on full ...

From Sensor sizes: Is full frame worth it?: For low light, events, and portraits with very shallow depth of field, yes. For travel, street, wildlife on a budget, and most hobby photography, a good APS-C camera with good lenses is enough, and you'll carry it more. Lenses and light matter more than the last stop of sensor performance.

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