tele converter x2 or extension tube on Tamron 17-50 2.8?

[phinix]

Can you use tele converter on Tamron 17-50 2.8? Will autofocus still work?
How about photo quality? Is it really huge difference, am I gonna loose a lot?

I read somewhere that those tele converters are only for bigger zoom with 2.8. Is this standard zoom ok to use with those tele?

Anyone used them on Tamron, or Sigma 18-50, or 17-70?
Can you show some examples please?

What about extension tube for macro? How big is quality drop?

 

[HoppyUK]

Teleconverters work best on longer lenses, usually over 200mm, but even then they are very rarely a good substitute for a longer lens on its own. Cheap TCs are generally very disappointing, 2x versions especially so. On top of that, you might have trouble getting one to physically fit something like a 17-50. You will be much better off with something like a 50-200 zoom.

Extension tubes should work quite well with a 17-50 at the longer end. Again you might have fitting problems, or maybe not. Check before you buy. You could also try supplementary close up lenses - no fitting problems there, and they are cheap. Check out Hoya, or Raynox. Depends what you want to do, and how critical you are.

 

[Stev]

I use a kenko 1.4 on my canon variant tamron 17-50 havent had the slightist bit of hunting since using it, focus is fine and iq is still excellent