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.

  • \$\begingroup\$ Can you get to a store to try them out? It's the only way of knowing for sure. \$\endgroup\$ May 25, 2011 at 14:57
  • \$\begingroup\$ @ElendilTheTall I do not know about any store around here where they have them both and let me try them. This is kinda smaller town in France where I'm now and will be for some time. \$\endgroup\$
    – Rasto
    May 25, 2011 at 15:12
  • \$\begingroup\$ Hmmm, that's a shame. Any photo shop should let you try before you buy. Perhaps you could telephone a store or two, even if they aren't very local, and ask them for their opinion; they might try the two lenses for you. \$\endgroup\$ May 25, 2011 at 15:24
  • \$\begingroup\$ @ElendilTheTall I'm thinking about going to Lyon tomorrow just to try the lenses.. But I might not be successful even there. It is sometimes very hard to deal with French shops really. Somewhere else it would not be much of a problem but here it is (if you spent some time here you would understand). And because I don't speak French and they don't speak English nor German (and of cause any other language I speak) it is even worse... I hope I'll find some store in Lyon that will allow me to try. But if somebody know the answer or part of it, please same me that journey and trouble. \$\endgroup\$
    – Rasto
    May 25, 2011 at 16:03
  • 2
    \$\begingroup\$ I know what the French can be like... :) \$\endgroup\$ May 25, 2011 at 17:13

1 Answer 1


The Sony 18-250mm is a slightly modified version of the Tamron 18-250mm. The Sony has quicker AF.

Both superzooms you mention have screw-drive AF however, and therefor neither are particularly fast. If AF speed is important to you I'd consider de the Tamron 18-270mm PZD, which has a built-in fast focus motor.

  • \$\begingroup\$ -1 If you read my question again and properly then you will know that I'm already considering it. In the fact my question is about Tamron 18-270 and not about Tamron 18-250. \$\endgroup\$
    – Rasto
    May 27, 2011 at 10:30
  • \$\begingroup\$ Ok no -1, I don't have enough rep. for that yet. But I'll cast that downvote when I have. \$\endgroup\$
    – Rasto
    May 27, 2011 at 10:36
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    \$\begingroup\$ No need to be so harsh - it was just to show that the Sony 18-250mm has reworked AF gears. There are also two versions of the Tamron 18-270mm, and the PZD version has the quickest AF of all lenses mentioned. \$\endgroup\$
    – Stijn.V
    May 27, 2011 at 18:14
  • \$\begingroup\$ Did you try it? What I'd like to know is exactly that: If the PZD version has quickest AF... \$\endgroup\$
    – Rasto
    May 28, 2011 at 12:55
  • \$\begingroup\$ I've only got experience with the Sony 18-250mm (found AF to be too slow, so I got the Sony 70-300mm SSM). The SSM motor is comparable to the PZD motor, so it definately should have the quickest AF, but I haven't got my hands on one yet.. \$\endgroup\$
    – Stijn.V
    May 28, 2011 at 15:33

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