You asked
Is the pentax hd d fa 28 105mm f 3 5 5 6 ed dc wr good for travel?
It's a sensible travel lens, with one caveat. Its 28-105mm range covers most of what you'll shoot on the road, from wider street and landscape frames to tighter portraits and details. The weather sealing is a bonus if you travel in rain or dust, and the compact size means it won't take over your bag.
The catch is that it isn't stabilised, so dim churches and evening food shots will need steady hands or a higher ISO. Its f/3.5-5.6 aperture also gets darker as you zoom in. On a K-1 or K-1 Mark II, it frames as marked. On an APS-C body, it behaves like 42-158mm, which is less wide than I'd like for travel.
Pair it with a small fast prime for evenings, as I suggest in the Travel guide, and it makes a solid one-lens-plus-one kit.
Written by Claude from this site's pages.