Look great, autofocus shame

The lens is a value-for-hammer. After the many tips tests on the web and in magazines, I've bought the lens, especially a close range of 95 cm with a high-intensity telephoto Klopper and the relatively low weight (Sigma and Sony more difficult) are real selling points for me.

A few test photos, on test charts, confirm: That thing is already open very useful sharp (at least in the extended middle and something else I never need personally at 2.8), recorded hardly abberiert tolerable chromatic (at 25 crushed megapixels on APS C Format drop the fringing naturally much more clearly than in the moderate pixel density of a full-frame chips, but there are virtually no border areas where the CA is particularly strong) and vignetting is at a full frame lens APS-C image circle also open no problem.

Now the two giants Abers come for me: The autofocus is slow and snoring - even worse - is not the sharpness with moderate lighting. So just focused over it. And back again, and get over it. That takes extra long, because you can not limit the Autofokusweg, so always travels the thing the whole way between infinity and 95cm. Now one could intervene, this will only work if you pull the focus ring to himself, and then the auto focus is quite out. The manual Fokusweg is so short that it is already a few tenths of a degree rotation about the sharp point over. Especially since you yes even in low light even with the electronic Super viewfinder of the Sony SLT-A77 the focus point can not be determined so precisely - in optical viewfinders (I know from 20 years F90X-per-experience) is it then quite difficult because of the lack of light ,

So far, so limited. But why I buy a bright 70-200mm? First: As a general telephoto. There is good and indemnifies nice, but it works well for a more compact appearance. Secondly: Because I want to have a chance of sharp images even when available light, the stop is hit or miss with a 4.5-5.6 because the incoming light back, yet neither is sufficient for any auto focus, I know for manual focus. For this, the Tamron is bad. Third: To sports or other motion capture quickly. For this, the Tamron is also not suitable - because of the short focusing path not even manually (which I know as mad unnerving).

Conclusion: Nice appearance, not for me to use. Then I'll have to bite the bullet, without chic close range, impose me a good 300 grams and 600 euros more, but hopefully with ultrasonic motor and accurate autofocus get what I want.

The price / optics ratio of Tamron lens but simply unbeatable!