Equipment: Canon Digital Rebel, Canon EF 100-400mm lens
The 100-400mm worked out fantastic when it was bright out. It didn't take long for me to realize that it was the "standard" at this type of event. More experienced photographers boasted 400mm lenses and up with extenders. Once it started to get dark, shooting with the 100-400 became almost impossible at f/4.5-5.6 even with the IS. I kept the IS in the Stabilizer 2 setting. Even with the ISO at 200 lots of noise was apparent from my LCD screen. I mostly shot in shutter priority mode with a minimum of 1/400 s sometimes even up to 1/1000 s. I found out that you need a lot of patience for the cars to fall into the right composition at the right point in the track during the right time of the day and not trying to screw up. Next time I will also bring a mono pod. It wasn't the weight of the lens that bothered me as much as the normal tendency to move slightly while aiming the almost 7 lbs of camera and lens. Even with the IS at 400mm slight blurring was apparent. Overall I was pleased that a majority of the images were sharp. I did focus more on composition and telling the story of the battle.