Originally posted by normhead I picked the prime.. the rendering was unmistakeable yet subtle. That said, I don't mind the rendering of the 18-250 either.. even at 1:1. Although I'm shocked ANYONE picked the Tamron as it is so far out focus in that test.
That aside, I'm thinking the primes are a bit.. hyped in the minds of their owners. Modern zoom lenses are soooo much better than ones even 10 years ago.. that I think the differences are quite subtle when the lens is focusing correctly. That is the hard part since Pentax only supports one adjustment, one has to adjust either for one side or the other with a zoom.
However, with primes, the only place where I see significant improvement over quality zooms are in Macro primes.. less distortion and they tend to be sharp from their fastest ap onwards.