In Focus – DAT GLOW!

We’re going to begin a new series of article here at called “In Focus” were Brian McKay, Tom Turk, Brad Plant, and I will share a favourite motorsports photo from the archives. We will discuss why we composed the image the way we did, what exposure settings we used, what techniques we deployed, and the story we wished to convey with the shot. We’re really fortunate here at to have some seriously talented professional photographers on staff to provide us with amazing imagery for you, our readers, to enjoy. I keep trying, as a part-timer photog, to achieve the awesomeness of the rest of our staff.

For the opening segment of In Focus, let me share with you a photo that I snapped at the Kansas Speedway for the Grand Prix of Kansas. This was a evening/night race, and as such, I was really looking forward to capturing the classic “glowing brake rotor” shot. Of course brake rotors heat up to glowing red hot temperatures during the daytime, too, but with all of the ambient light, it’s difficult to discern the glow. As the sun goes down and the level of ambient light also decreases, the brake rotors light up like beacons. One thing that surprised me, however, was that it wasn’t just the front rotors that heated up to the point of glowing, but that a car with properly balanced brake bias will light up all four rotors!

This was captured in the braking zone to Turn 1 of the Kansas Speedway’s infield road course. During previous practice sessions, I’d noticed and captured rotor glow, but the glowing rear rotors was something that I didn’t notice until the race at night in the huge brake zone approaching Turn 1 after accelerating around the oval from the Oval Turn 2. When I noticed it standing at the SCCA corner worker’s station at Turn 1, I moved up track to be at a position where the brake heating would be at a maximum. This is exactly the type of shot I wanted. I wanted the car to fill the frame and perpendicular to my line-of-sight with a slow enough shutter speed to smooth the background, the tire printing, and the wheel spokes. As a physics and astronomy teacher, I also plan on using this image in the classroom when talking about blackbody radiation and how the brightness and colour changes around the rotor as you get more distant from the brake calipers. Lots of good teachable moments going on here.

Well, before I completely geek out on the thermodynamics here, let me fill you in on the settings I used to shoot the image. Here’s the EXIF data:

Device: Nikon D7000
Lens: 70-200mm f/2.8G
Focal Length: 165mm
Focus Mode: Manual
AF-Area Mode: Single
Aperture: f/4.5
Shutter Speed: 1/100s
Exposure Mode: Manual
Exposure Comp.: 0EV
Metering: Center-Weighted
ISO: ISO 3200

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One Thought to “In Focus – DAT GLOW!

  1. Rick B.

    Very cool – I like almost all of your photos!

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