Any decent telephoto lens should be okay. Actual examples.
IMAGE LINK: http://i1174.photobucket.com …023a0000b_zpszw0spsnb.jpg
on photobucket
Camera Maker: Canon
Camera Model: Canon EOS 60D
Lens: 70-300mm
Image Date: 2011-10-23 10:13:17 (no TZ)
Focal Length: 300.0mm
Aperture: ƒ/7.1
Exposure Time: 0.0025 s (1/400)
ISO equiv: 320
Exposure Bias: none
Metering Mode: Matrix
Exposure: program (Auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
IMAGE LINK: http://i1174.photobucket.com …023a0000a_zpshhnkrlbl.jpg
on photobucket
Camera Maker: Canon
Camera Model: Canon EOS 60D
Lens: EF-S18-200mm f/3.5-5.6 IS
Image Date: 2011-10-23 08:27:02 (no TZ)
Focal Length: 175.0mm
Aperture: ƒ/6.3
Exposure Time: 0.0020 s (1/500)
ISO equiv: 1000
Exposure Bias: none
Metering Mode: Matrix
Exposure: shutter priority (semi-auto)
White Balance: Auto
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
adam.willison wrote in post #17881637
Hey all,
I'm gearing myself up to become a karting photographer in the not too distant future, and I'm trying to plan my gear accordingly. The question I have is about how much focal length I'd need. I have shot a couple of events, one with a 70-200 and one with a 100-400, both on crop sensors. The first time I felt like I didn't have enough length, and the second I felt that I didn't need as much, so I'm trying to get a feel for what others might be using.
I've been looking through some metadata of some old shots of myself (former racer) by some pro's and seeing a lot of shorter lengths than I expected, yet a lot varied. From 200mm on full frame up to 600mm on a 1.3x crop.
I had pre-set my mind on a 300 f4 on a crop as my main camera, and either a 24-105 on a crop or a 70-200 on FF as my backup, but now I'm not sure.
Any advice to help me find my feet would be greatly appreciated

Adam.