What is the pentax smc da 300mm f 4 ed if sdm good for?

Here is what the site says about that.

From [Pentax smc DA* 300mm f/4 ED [IF] SDM: Pentax smc DA* 300mm f/4 ED [IF] SDM](/gear/lenses/pentax-smc-da-300mm-f-4-ed-if-sdm/): A prime lens by Pentax for APS-C cameras, 300mm f/4. A weather-sealed telephoto prime for wildlife. Specs - Maker: Pentax - Focal length: 300mm (prime) - Maximum aperture: f/4 - Made for: APS-C sensors - Mounts: Pentax K - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Pentax K): like 450mm on full frame; f/4 gives about the depth of field of f/6 there. - On ...

From [Pentax smc DA* 60-250mm f/4 ED [IF] SDM: Pentax smc DA* 60-250mm f/4 ED [IF] SDM](/gear/lenses/pentax-smc-da-60-250mm-f-4-ed-if-sdm/): A zoom lens by Pentax for APS-C cameras, 60-250mm f/4.

Quoted from this site's pages.