Pentax smc da 18 55mm f 3 5 5 6 al wr vs pentax 18 50mm f 4 5 6?

Here is what the site says about that.

From Pentax smc DA 18-55mm f/3.5-5.6 AL WR: Pentax smc DA 18-55mm f/3.5-5.6 AL WR: A zoom lens by Pentax for APS-C cameras, 18-55mm f/3.5-5.6. The weather-sealed version of Pentax's long-running kit zoom. Specs - Maker: Pentax - Focal length: 18-55mm (zoom) - Maximum aperture: f/3.5-5.6 (it gets darker as you zoom in) - Made for: APS-C sensors - Mounts: Pentax K - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Pentax K): like 27-82mm on full frame; f/3.5-5.6 gives about ...

From [Pentax smc DA 18-135mm f/3.5-5.6 ED AL [IF] DC WR: Pentax smc DA 18-135mm f/3.5-5.6 ED AL [IF] DC WR](/gear/lenses/pentax-smc-da-18-135mm-f-3-5-5-6-ed-al-if-dc-wr/): A zoom lens by Pentax for APS-C cameras, 18-135mm f/3.5-5.6.

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