Fair enough Alec but the Tamron lens you had was not the 17-50 or 28-75 f2.8 (which is well regarded as very sharp lens) as I said it is sharper then my 17-40L which is sharp
There maybe some dodgy Tamrons out there but I can assure you there are some dodgy Canons and Sigma's also 
Ricky
Go figure.

