Canon T6i for Wildlife Photography

JPG73 wrote:

I am considering purchasing a Canon T6i to use for Wildlife photography with either the 70-200 F4 IS or the 100-400 IS.

Unless I knew I could walk up to something big, I would not set out to shoot wildlife with a 200mm lens. 100-400 II is the versatile wildlife choice in the Canon range, without having to spend new-car money.

I was wondering if the autofocus is adequate to focus these lenses on deer and birds.

If it is accurate with your particular lens and camera then it's more than adequate, but if your combination isn't accurate there's nothing easy you can do to fix it.

Also, is the lack of micro focus on the T6i a good reason not to buy the camera?

If you plan to use long lenses (300+), and focus accuracy is critical (e.g. feather and eye detail on birds), then sooner or later you will have a problem that's hard to solve without AF MA. The original 100-400 often needs a lot of AF MA, so I wouldn't recommend that with a Rebel unless you can test it and it's perfectly accurate on your camera.

Would I be better advised to purchase the Canon model 80D at the higher price?

Any recent model with AF MA will be a better prospect in that respect, so don't discount the 70D, 7D, and 7D II. Those cameras are also better suited to those tasks than a Rebel, as is the 60D (which doesn't have AF MA), and the 50D (which does have AF MA, but... nah...).