Teleconverter 2x or 1.4x

[Thomas68]

I have a Canon T6s with a Tamron 18-200mm lens. I would like to get a teleconverter for it, but I don't know which one to get. I mainly shoot wildlife and birds. Which one is better for this? I really can not afford a 500mm lens and up right now. 

[kvbarkley]

The 2X will probably make autofocus very difficult.

You will probably find that it is better to crop than use the converter. I joke that the two happiest days in a photographers life are the day he first gets his teleconverter and then the day he stops using it.

[shadowsports · Accepted solution]

I think both of us owned the T6s and kvbarkley might still have his.  Great camera.  I would not try to pair the 18-200 with a TC.  

Tamron's TC's.  Gordon Liang of Camera Labs said the AF fails on the Canon version with older Tamron lenses. The 18-200 came in several variants, but the primary 2 were B011 and B018. The latter being the one you have since the B011 was Sony and Canon EF-M mount. 

This leaves you with a Canon or 3rd party TC, and I believe you'll be disappointed by either because of the lens and regardless of whether you chose the 1.4 or 2.0.

Truly, I believe the best option would be a Sigma or Tamron 150-600 series lens.  I understand its twice the cost of a TC, but it would serve you much better with your current camera or future body.   

[kvbarkley]

Yeah, I still have my T6S. I also have a 150-600 and a 1.4 teleconverter, but I rarely use the TC because it is such a hassle. Believe me, I know the TC is tempting, but in the end it is not worth it.