What are the alternatives to the pentax hd da 21mm f 3 2 al limited?

The closest alternative on the site is the Pentax HD DA 15mm f/4 ED AL Limited. It's also a prime for APS-C cameras, but at 15mm it's wider than the 21mm, so you'll get a bigger view and more of a scene in the frame. It's also slower at f/4 against the 21mm's f/3.2. I don't have more detail on it here, so check its page for the full specs and the list of cameras it fits.

If you're not set on a Pentax Limited, the lenses guide explains which focal lengths suit which kinds of shooting.

Written by Claude from this site's pages.