... the Pentax DA 18-250 and here are sample pics (showing the zoom range)

and

a link to some large files done with the Pentax DA 18-250 @ the 250 end :shocked;

Granted the DA 18-250 is a little more expensive than the DA 18-55/50-200 combo but it is virtually
the same price as the Tamron 18-250 and I have found, from personal experience, the less you have
to change lenses the better

Cheers,

Jack