The optical system, construction, and exterior are the same as the EF 75-300 mm f/4-5.6 III USM’s. The difference is that it uses a DC motor instead of a USM to drive the AF.
25A DC motor is used instead of a USM to drive the AF
13 elements in 9 groups
Front group rotating extension system with Micromotor
Closest Focusing Distance: 4.9 ft./1.5m
I used this lens at the 2012 Indian Wells Professional Tennis Tournament. Inside stadium shooting at night was very disappointing as I could not used a flash. With courtside seats costing $100.00 a piece, I had expected to get very sharp pictures of the greats. Not so. the focus was very uneven and blurry around the immediate subject matter causing distraction to the eye. The highest shutter speed I could attain was 70/sec. I used the sport shooting mode and the manual mode. I also used a monopod to improve steadiness but this still did not achieve the result I was looking for. The lens performed better in bright daylight but late afternoon light once again degraded sharpness. It was too bad because the compostion of my pictures was good. I welcome any advice as to how to improve my technique using this lens from more experienced and better photographers. My email is attached.
When I first used this lens I was a rank amateur so I had no idea what I was doing. Now that I have advanced beyond my kit lenses, the limitations of this lens are glaringly apparent. My major problem with is the fact that you cant use a polarizer or split ND filter with it due to the external focusing mechanism.
This is a very good lense for the price. I take lots of sport action shots and it works very well. I have looked at other lenses that are over $1000 and they offer more quality but when viewing pictures from both, you can't really tell a difference.