Basil wrote:
After reading a ton of reviews and looking at sample images, etc., of many different lenses, I concluded that for my 7D crop sensor this was probably the best "bang for the buck.". On a crop sensor it is equivalent to 480mm and if I add the 1.4x extender it would be like a 672mm on a full frame and still have equivalent f-stop of 5.6. With IS I imagine its possible to squeeze another stop or two out of it.
I can't wait!
I use it frequently with Canon EF 1.4X II for a combo equivalent to 420mm f5.6 and it works very well.
This was done with the lens & teleconverter on 7D, handheld...
And this was shot with the same lens + TC on 5DII, where it works equally well...
In more challenging, low light conditions AF can slow down or hunt a little more when the TC is added to the lens... Not really surprisingly, but also pretty minor difference that I've only seen occur in really demanding lighting conditions. In better light, it probably slows with the TC on the lens... but not enough that I notice it. I've tracked race cars at 100+ MPH with the lens + TC, no problem.
One nuance of this particular lens is it's tendency to render a magenta tint to specular highlights, such as can be seen in this hawk's eye...
This is easily fixed in post-processing, if it's a problem. I didn't think it was in the above image, so left it alone.
If you are looking for a TC to use with it, I certainly can recommend the Canon 1.4X Mark II, if you can find a good, used one (usually around $250). The Mark III should work just as well, but will cost a lot more (typically about $450).
I haven't used, but hear great things about the Kenko Pro 300 1.4X DG and DGX (about $250) and the Kenko MC-4 1.4X DGX sounds to be nearly as good (approx. $150). I've also heard some good reports about certain Tamron and Sigma TCs, but don't know the specific models and each has made a lot of different ones over the years.
I have Canon 2X II, but I don't use it on this lens.
Enjoy the lens!