I might point out Mattb123 in the 18-135 lens thread. Us non-motorized outdoor types for the most part prefer the 18-135.
DA 18-135 WR, Show us what it can do - Page 217 - PentaxForums.com
At this point you'll notice a clear difference in the recommendations of other trippers, and over-night non-motorized enthusiasts and those who who don't really understand how demanding tripping is. You carry a lot of weight for a lot of distance.
Tent, sleeping bag, air mats, food, cooking lit, it all adds up, at the start of a trip one pack can weight 70 pounds.
You reach a point where an extra half pound means you can't lift or carry your packs. You go from "piece of cake" to "I can't do this" with an extra pound of weight.
I guess if you haven't been there and done that it's hard to understand. But Tess and I carry our limit on a regular basis. Packs so heavy you're afraid if you put them down, you'll need help getting them back up.
So why would one take an extra 150 grams for a lens with less range and nearly identical IQ ratings for a trip when 99% of you images are going to be ƒ5.6 or ƒ8?
Tripping is about doing more with less. The DA*16-50 has it's place, but not on canoe trips....
And I really hope people will stop filling the thread with DA*16-50 images. We know you can do it. I can shoot portraits with a 300mm lens, I can shoot moose or bears with wide angles, if I don't value my life. If you can only use one lens you can take everything with it, as those of us who grew up with an SV and 55mm 1.8 can tell you. But that doesn't make any of these lenses appropriate for the job.
Over the years there have been a lot of bull headed, obstinate first time photographer/trippers who didn't listen to my gear recommendations for tripping. Every one of them regretted it.
I understand a lot of people are enamoured with their lenses and will recommend them for anything any time to anyone.
But come on dudes, try and understand the context.
I almost wish I could divide the responses into two groups, non-motorized overnight hikers or canoe trippers in one thread, and day trippers who spend most of their time with the camera on their back seat on the other. You'd have two completely different recommendations. The difference being, once you've taken a trip where you overpacked and the weight ruined your enjoyment of the trip, you know the consequences of not shaving every gram you can.
And if you do overpack, it won't be an afternoon of discomfort like on a day hike. You'll experience it every day for a week or more, and you'll know it's coming. Kind of like a friends dad who used to hang the belt on the wall in the morning before school if he was going to beat the kid when he got home. You not only get the discomfort, you get the anticipation of the discomfort, often for a week or more.