Ypu received some goo advice above. I travel a lot and in needs for a compact 'travel' lens.
I have two 'travel' all-around lenses: DA18-135mm and DA18-250mm. The former is compact and WR. The latter has a longer reach, but can only be found 2nd hand. Both are excellent travel lens, whe you need to travel light and do not want to swap lenses. They are both light, compared to the Sigma 18-250mm, another valid suggestion. After nearly 4 years of travel, I tend to favor my DA18-250mm for the extra reach, as well as the lens sturdy construction. (THe DA18-250mm is not WR, but very, very sturdy.)
The down side of any 'travel' lens is low light. For that reason, a number of Pentaxians (incl. myself) travel with a spare fast fifty in the pocket: a fast lens like a 50mm f 1.4.
In my case, I favor strongly my Voigtlander Nokton 58mm f1.4 to complement my DA18-250mm (or my DA18-135mm), The VL58mm is MF, light, solid (metallic body) and great IQ.
I add that I shoot a lot outdoor sceneries for which the VL58mm is a great lens. In my case, my VL58mm f1.4 works as both low light lens and my special lens when I want to take some special lansdcape scenery in poor contrasting lighting (eg smog, smoke, fogg). The VL58mm excels in these situations (
https://www.pentaxforums.com/userreviews/voigtlander-58mm-f1-4.html).
Hope that the comment may help.
Last edited by hcc; 01-01-2015 at 11:50 PM.