teleconverter with Tamron 28-75mm Di

[sunny16]

Hi, I'm new here! I am planning a trip to Europe and I'm trying to pack light. My main lens will be the new Tamron 28-75mm f/2.8 Di on my Pentax *istD. I want to get a teleconverter for it because I'll be spending most of my time in a city and I don't think I'll need to go much longer than 75mm. I'm trying to figure out which one to get.

I know the Kenko/Tamron teleconverters have gotten high marks from users online. My other choices are Tokina and Sigma, but I know the Sigma might not fit this lens. I have heard that the optical quality of the 1.4 teleconverters is better than the 2x, but I understand that this can vary. Help! I'm lost here!

Anyway, if anyone has experience with a teleconverter that they love, or even better, with this new Tamron lens, I'd love to hear your opinions or see samples.

Thanks,
Sunny16

[Mongrel]

I can tell you that the Sigma 1.4x EX APO teleconverter will NOT work with this lens. The Sigma is designed similar to the Canon and has a protruding ring that goes *into* the back of the lens. As far as I know, both the Canon and the Sigma will only work with zooms from the 70-200 and up and primes from the 135mm focal length and up. It's a shame because the Sigma (and the Canon) are top quality teleconverters. Sigma and Canon both list the lenses that will work with their tc's on their websites.

I don't know anything about the Tamron or Kenko teleconverters other than that some people have had GEAT success with them. I believe that the Tamron will fit a broader range of lenses but I can't provide you with which ones.

I recommend going to the Tamron website and seeing if they have a compatability chart listed there.

Good luck with your quest...