Pentax 18 270mm f 3 5 6 3 vs pentax 18 250mm f 3 5 6 3?

Here is what the site says about that.

From Pentax smc DA 18-270mm f/3.5-6.3 ED SDM: Pentax smc DA 18-270mm f/3.5-6.3 ED SDM: A zoom lens by Pentax for APS-C cameras, 18-270mm f/3.5-6.3.

From [Pentax smc DA 18-250mm f/3.5-6.3 ED AL [IF]: Pentax smc DA 18-250mm f/3.5-6.3 ED AL [IF]](/gear/lenses/pentax-smc-da-18-250mm-f-3-5-6-3-ed-al-if/): A zoom lens by Pentax for APS-C cameras, 18-250mm f/3.5-6.3.

Quoted from this site's pages.