Just got my Tamron 18-250mm lens and have been doing some very preliminary testing. As with all (I think all) INTERNAL FOCUSING lenses, you don't get the full zoom range unless you are focusing at or near infinity. I must admit that I was hoping otherwise.

The lens focuses reasonably fast but unlike the Pentax Kit lenses, you have to take the lens out of AF or CAF if you want to play with a bit of focus tweaking. It does find focus reasonably fast. Construction appears to be very good.

I am hoping this lens will allow me to replace my 18-55 and the 50-200 with just one lens. However, with these two Pentax lenses the focusing is external even though the front element doesn't turn during focusing and thus you get full zoom range at any distance.

As a walk around lens this should be a dream since the lack of full zoom appears to be directly related to the distance from the subject. Since I tend to shoot people at distances greater than 50 feet I will not feel the full impact of the internal focusing issue.

Jerry