You asked
Pentax 16 85mm f 3 5 5 6 vs pentax 18 55mm f 3 5 5 6?
Both are Pentax zooms for APS-C cameras with the same f/3.5-5.6 aperture, so the choice comes down to range and what you want to carry.
The Pentax smc DA 18-55mm f/3.5-5.6 AL WR is the light, sensible starting point. It's the weather-sealed version of Pentax's long-running kit zoom. It isn't stabilised, so keep your shutter speed up.
The Pentax HD DA 16-85mm f/3.5-5.6 ED DC WR starts wider and reaches much further, so it can cover more of a day out without a lens change. It's also weather-resistant. I don't have stabilisation or weight details for it here, so check those before you buy.
My pick: for a first lens on a budget, the 18-55. If you want one zoom to do most jobs, the 16-85. For wide scenes, see landscape lenses.
Written by Claude from this site's pages.