I want to buy either Sony 18-250 F3.5-6.3 or the new Tamron 18-270 F3.5-6.3 as a travel lens for Sony A55.
I have found good reviews that told me quite something about image quality of these lens. The graphs of sharpness, distortion etc. at http://www.slrgear.com (Tamron here, Sony here) can be used for quite objective comparison of optical quality.
However, most important think for me here is autofocus operation. Slow or too noisy AF (AutoFocus) can drive me mad... I hate to miss good shots.
I cannot find comparison of AF of these two lens. Reviews that I have found are more confusing than helpful when it comes to AF speed.
So does Sony 18-250 have faster AF? Or is it opposite? How does their speed compare to A55's kit lens? Is either of them usable for continuous AF? Which has more quiet AF?
Please, do not advise me to not to use superzoom. I know why I want it.