Is the pentax hd da 560mm f 5 6 ed aw worth it?

Here is what the site says about that.

From Pentax HD DA 560mm f/5.6 ED AW: Pentax HD DA 560mm f/5.6 ED AW: A prime lens by Pentax for APS-C cameras, 560mm f/5.6. A super-telephoto prime for birds and distant wildlife. Specs - Maker: Pentax - Focal length: 560mm (prime) - Maximum aperture: f/5.6 - Made for: APS-C sensors - Mounts: Pentax K - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Pentax K): like 840mm on full frame; f/5.6 gives about the depth of field of f/8.4 there. ...

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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