I post processed both pics about the same. The 300 II + 1.4 T.C. held up pretty good.
There is a definite difference when viewed at 100%.
This first one is with the 300 II + 1.4 T.C. Field of view is 672 MM. on a full frame sensor.
The 7D and the 300 with the converter is pretty good. I do believe if the 7D had a current up to date sensor it would be much closer. I had to do a lot more PP as in de-noise for the 300 to clean up. Just a lot more work in Post cleaning up the 7D pic.
I am starting to get excited about the new Pentax K-3. If that materializes with the specs being thrown around.
We will have an exciting review on our hands. I would love to see how a high MP camera with the Sigma 300 mm F/2.8 and Sigma 500 mm F/4.5 compare next to the Canon glass. With Canons very dated sensor technology.
Personally I am really excited about the possibilities. Sigma is not as sharp as the Canon glass. But with new sensor technology and better AF? Then it may level the playing field quite a bit. Especially against the 7D. If as good as the Mark IV I would use the Sigma gear. It is small, light, and sharp enough IMO. With Pentax 4 stops in body stabilization. WOW. Way to early to speculate at this point, but I will be running the tests for sure.
After doing this test I am convened that a high MP high quality sensor with a decent telephoto lens will produce some excellent results!
Wait and see...