Originally posted by Dan Rentea You'll probably gain in terms of af speed, but you'll have the same problem that you told me I have when we discussed about Sigma 150-600mm lens: the f6.3 aperture on the maximum focal length.
But, Pentax lens has some nice advantages: it is weather resistant and it is small and light compared to Sigma.
That does concern me, the 6.3 thing, more so the fact that my wife wouldn't be able to use it on her K-5. Every day she takes the dogs for a walk across a couple of ridges with steep drops. Often we get Ravens , Hawks, Crows or Turkey Vultures playing in the updraft created by the ridge. We usually don't take the bigger lenses, it's a rough hike and often involves bush whacking. We know where we are going but there are no marked trails, and I've been confused a few times. So the lens would be bought specifically for those times. Bright light, a sky to create image separation (not bokeh) relatively close subjects. I think it could work great. Unfortunately she walks more than I do, and the lens won't work on her camera. So I have to buy her a K-P or something to use it with. That makes it pretty expensive.
The 6.3 thing limits the use of the lens in many ways, I wouldn't want one as an only lens, but if you buy it, you accept that limitation, As long as you use it for what you bought it for, you don't have a problem. Now if you take it when you should have taken your DA"300 or Tammy 300 2.8, that's a problem, your problem, not a problem with the lens.
Of course I would also say, having a 6.3 lens for morning or evening images is going to be a no go, and many of the best wildlife images are morning or evening. It won't end up getting taken on canoe trips. But for casual walks hither thither and yon in good light, it's kind of a no brainer if you can buy one for that reason.
---------- Post added 11-16-17 at 05:35 PM ----------
Originally posted by SSGGeezer I would be happy to Norm, Just the idiots in congress and such made it so I need a Passport or Passport card to visit friends and distant relatives in Canada now. I have driven across Ontario before just to stop and say hello to people I met online, and then at a computer get together in Houston, TX. so I am willing to travel. You appear to live in a beautiful area so it would be like here but with more snow!
We should really have a whole Pentax gathering up here sometime. There's lots of hikes and things to introduce to your camera.