What is the reasoning with not bothering with the 2X converter on a crop body, a 1.4X would only give me 448mm equivalent, a 2X would still only give me 640mm equivalent, whereas I am already used to running out of zoom at 800mm equivalent.
If for some reason it would degrade the image below the quality of the Sigma then it would be a waste, if it is only (only ha) for the 2 stops of light lost with a 2X converter, that would make it the same as the Sigma at 150mm and a whole 1/3rd of a stop better at full reach all be it less reach than the Sigma!
What I'm trying to say is that I'd love the extra reach but I'm open to reasoning on why not to?
Here I am debating something that could be months away!
Aaah the planing stage!