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11-11-2009, 11:26 AM   #1
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Have a k200d, Tamron 75-300mm AF, any suggestions on which teleconverter will work with this combo? Seems the Tamron 1.4 is no longer available and need help with decision, any feedback would be appreciated.

11-11-2009, 11:42 AM   #2
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If you browse these forums (including the Lens forum) you'll see the common advice is to forget the TC. Except when using the very best (= most expensive) lenses to begin with, and pairing them with the very best TC's, you almost always get results that are *worse* than simply shooting your 75-300 as is and then cropping the results. And not just a little worse - really, quite a bit worse.
11-11-2009, 12:35 PM   #3
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Indeed this issue has been discussed many times, and it's the common conclusion that the TCs are a nightmare to use on lenses they're not designed for.

The Tamron 1.4x TC was designed for fast telephoto lenses like the Tamron 70-200. Any slower than f/4, and autofocus becomes horrifically unreliable. On top of that, with consumer level telezooms such as the Tamron 70-300 or Pentax DA 55-300, the autofocus may work, but it is extremely slow, hunts and creates very dull and poor contrast images.

It's not worth it - just shoot with the zoom on its own and crop.
11-11-2009, 01:14 PM   #4
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Thanks for the info, sounds like something to avoid and save for a longer lens, thanks for your time!

11-17-2009, 05:56 PM   #5
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..but if you really want to insist going this route, you can try the:
Tamron 1.4X TC (you can still find some used but very exorbitantly priced)
Kenko 1.5X TC
Pentax 1.7X TC (high priced too)
Promaster 1.7 TC

The Kenko is the only that is still offered brand new.
All the other ones you have to find for sale "used".
Hope this helps!

You would also want to use it with a tripod for better results.

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