Tokina 300mm f/2.8 AT-X 300 AF PRO
(From Tokina lens literature) The AT-X 300 AF PRO is a wide aperture telephoto lens, which provides high definition and super sharpness even with the aperture wide open at f/2.8. Two large SD glass elements in the first optical group correct chromatic aberrations and create accurately focused color. This exceptional optical performance is maintained down to its minimum focus distance of 8 feet (2.4 meters). The external textured "armalite" finish and rubber grips improve handling as well as adding a distinguished look to this performance lens.
The patented IRF (Internal Rear Focusing) system yields quick and reliable auto focus by only moving smaller elements in the rear of the lens to achieve focus. The nine bladed aperture creates a more circular light path which in turn gives more even illumination across the frame, reduced diffraction at small apertures provides more pleasing appearance to out of focus highlights.
Tokina 300mm f/2.8 AT-X 300 AF PRO User Reviews
10 out of 10 points and recommended by wmvaux (1 reviews)Sharp, Solid, quick auto focus, great bokehHeavy
I found a guy on the internet who bought one of these lenses second hand and he had amazing shots.reviewed March 11th, 2014 (purchased for $960)
The great thing about this lens is it's around a quarter to a third of the cost of an equivalent Nikon or Canon lens and it does an awesome job.
Sadly Tokina don't make these any more, but have seen a number on places like ebay which is where I bought mine.
I use this lens for sports and action photography and also birds, animals and it's a great lens to take portraits with awesome bokeh around 30 yards (25 metres) away.
I sometimes use a 1.4 teleconverter which turns it in to a 420mm at f4 which is fantastic.
Highly recommend to someone who can't afford the Nikon or Canon equivalent which can be thousands of $$$ more.