Quote: It is always best to back up any claims you make regarding faults imo.
Tamron lenses are normally very good and i have never had an issue with any so i am thinking you got a dud but it is a shame if it puts people off the scent of this lens.
Right. Rushed it a little bit there.
Below a screenshot of 100 % crop of two pictures, the left one with a correctly focusing Sigma 28-105 at 105 mm/4.0, at the right the Tamron 17-50 at 50 mm/2.8. Both wide open, focus AF-S with the center point chosen pointed at the tip of the pen.
Illuminated by indirect flash, the shadow of the pen shows about where the focus should be.
Next one shot in two magnifications, 50 and 100 %. 17 mm at 2.8, flash, AF-C, center point chosen, at the tip of the pen.
You could probably live with the first examples if it wasn't for the last. Imagine trying to keep your digital archive of paper clippings with the camera like I'm used to.
It's not beneficial for portraits either, although the evidence is less conclusive here:
less conclusive since you cannot exactly reproduce it. Flash (low ambient light), 50mm/f2.8, AF-C automatic point selection.
Sure, there are some sharp shots among my portraits like this. But where you can verify what and what you focus on, it's off.
Since it's been my favourite lens with KM I'm looking forward to getting an unflawed one.