Tamron Tele-Converter

[Conk]

I picked up a Tamron AF Tele-Converter 2x C-AF BBAR MC-7. I heard that using it on anything more than a 200mm causes concern for chromatic aberration.
Any thoughts on this?

[scottbergerphoto]

In general 2x teleconverters cost you 2 stops of light, and reduce the quality of the image regardless of the lens you use. If you have no choice, use it.
Scott