Best wide angle lens for the pentax k 30?

Here is what the site says about that.

From Pentax K-30: Pentax K-30: A DSLR by Pentax with a 16.3-megapixel APS-C sensor, announced in 2012. Specs - Maker: Pentax - Mount: Pentax K - Sensor: APS-C, 23.5 x 15.6mm, crop factor 1.5 - Resolution: 16.3 megapixels - Stabilisation: in the body - Announced: 2012 - Type: DSLR Focal lengths on it Lenses frame like 1.5 times their focal length on full frame: 16mm like 24mm, 23mm like 35mm, 33mm like 50mm, 57mm like ...

From Laowa 15mm f/4 Wide Angle Macro: Laowa 15mm f/4 Wide Angle Macro: A macro lens by Laowa for Full frame cameras, 15mm f/4. An ultra-wide that focuses to 1:1.

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