This is Danny Smith racing in 600 superstock at Mallory park in the Emra race series, Sunday May 15th. I Used a Sigma F2.8 120-300 zoom with a Sigma X2 converter at 600mm on a Nikon d7000 body to take this. Been experimenting with F stops as I've been disappointed in the results with this set up so far. It was took at F:14, 1/800 with iso 560. Still not as sharp as a 600mm prime but this set up is 1/4 of the cost of the big lens.