need some advice on a x2 converter

[a200kev]

am looking in to getting a x2 converter for my sony a200 iam using a tamron 70-300mm lens iam well in to my motorsports photographary mainly motorcycles i and was wondering if the converter lens would be a good move or not ive got my eye on a few good ones at the mo tamron and sigma there the proper byonet type fitting just wondering if there any good or they just rage havock on the auto focus ?

 

[Dal]

I know its not the same camera or lens but when I got my 70-200 f2.8 it came with a x2TC so I wanted to try it out with the 70-300 I was upgrading from. The TC didn't even fit onto the back of the lens as the rear lens element makes contact with the TC, pretty sure it would be the same for the Tamron lens though.

 

[andrewc]

Even if it fits your lens, chances are you'll loose autofocus and the image quality would be poor.

Get a better quality lens and/or crop.