Top positive review
20 people found this helpful
on 7 September 2013
I've bought this as the best option for high image quality in the up to 200mm f2.8 zoom lens region on my Pentax K-30 without spending over £500 or so. The Pentax 60-250 f4 would match it optically but it's not as bright and costs over twice as much but does have quiet AF whereas the Tamron is body driven screw drive old school AF. The HSM Sigma 70-200 f2.8 isn't in the same class optically by all accounts so I never considered it, it's also much more expensive. Pentax cameras from the K-7 on are quite fast with most screw drive lenses though, they have torquey motors and this made this Tamron a viable option on the K-30 (in theory anyway).
Testing the lens, it meets all my expectations for image quality. I found a little body AF adjustment made it even better as it was slightly front focusing at f2.8 - it's as sharp as zooms ever come - as good as most primes in fact throughout all of the 70-200 range. f4 seems to be a bit sharper than f2.8 but f2.8 is fine. I took a load of cat pictures indoors focusing on her nose from across the room and every pore and whisker was razor sharp. Focus holds good if the zoom is adjusted after an AF lock - a handy quality. Smaller apertures are also great, maintaining sharpness, important for obtaining deeper depth of field when needed. The AF is fast enough but there may be the odd hesitation and fine adjustment in time honoured Pentax screw drive tradition - I think release priority rather than focus priority in the K-30 will sort that one out. It's nowhere near as noisy as a lot of screw drive lenses. As long as the main priority is image quality, which it is for me, it's a great lens.