Infineon: Raceway Focusin'
In yesterday morning’s post regarding my last-weekend experiences at Infineon Raceway, I commented, "I’ll pass along my DSLR experiences and 6.1 Mpixel results in a future post." This’d be that post. But before I begin, I may owe some of you an apology. A friend of mine who read my earlier writeup commented last night:
You need an agent to screen your self-portraiture. The image you offered could lose you some readers, or perhaps just get you some laughs.
My intent was certainly to get some laughs, but it definitely wasn’t to lose readers. So if your sleep was plagued with nightmares after viewing my visage, I’m eversosorry and blame it on the camera phone ;-).
I spent most of my time Saturday behind the Turn 2 fence and other barriers. As you’ll note from the Raceway website, the course layout changes depending on the event. Turn 2 was nearby Infineon’s hospitality tent, so I could quickly recharge with cold soda and water when needed during the hot day. And although I’d never photographed the Raceway as a media rep before, the dozen-or-so other folks around me were suggestive that I’d picked a good spot.
Turn 2 is at the end of a fairly long, fairly straight stretch of track, so the cars pick up quite a bit of speed prior to approaching the turn (and consequently need get on the brakes pretty hard in order to successfully traverse it). There’s also a gentle upward-sloping hill between Turns 1 and 2, which causes the cars to ‘pop’ into view if you’re situated at the apex. As I mentioned in my previous post, I had two first-generation *ist D DSLR bodies with me, whose autofocus capabilities Pentax improved in subsequent-generation cameras such as the 6 Mpixel *ist DS and K100D and the 10 Mpixel K10D. But until I was in the ‘heat of the action’, I didn’t realize just how limiting the *ist D’s first-generation autofocus shortcomings would be.
In fairness to Pentax, part of the problem was the lens. I did most of my shooting with the Sigma 170-500mm zoom, whose maximum aperture limitation (f5 at 170mm, f6.3 at 500mm) presented the mated camera with a non-optimal amount of light (as compared to, for example, my Tamron 300mm f2.8 fixed focal length telephoto, which I also had with me but decided not to use). However, it was a bright sun-lit day; a quick scan of the EXIF data in my photos suggested that the camera was able to shoot at f11 and smaller apertures even with shutter speeds of 1/1000th of a second and faster.
I quickly realized, thanks to the ability to zoom in on a portion of a captured image on the camera’s 1.8" LCD, that the traditional ‘auto’ focus point setting just wasn’t going to work. The camera’s auto-focus ‘brain’ kept getting confused and locking in on something in the background instead. So auto-focus accuracy was to some extent a problem all day.
Center-point auto-focus, which I tried next, worked better. In this case, however, I ran into my second stumble; auto-focus speed. The *ist D offers two auto-focus modes. In AF.S (single), auto-focus locks when you partway depress the shutter. As a consequence, the shutter won’t trip until the camera decides that the main subject is in focus, so if the car was moving too fast (or depending on your perspective, the camera was working too slow) I’d miss the shot.
With AF.C (continuous auto-focus), the camera’s shutter fires whenever I press the release button…which got me a lot of shots, but most of them out-of-focus. It’s a good thing I was using Seagate 8 GByte CompactFlash HDDs! I even tried switching to manual focus and triggering the shutter whenever the car reached a certain point on the track, but unless the aperture was very small to maximize depth-of-field, I’d still end up with lots of slightly-out-of-focus results…and of course, small apertures translate to slow shutter speeds, which cause blur with fast-moving subjects.
With that all said, I did get some pretty good shots, if I do say so myself. Enjoy the small sample of images that follow (click on a photo for the full-res version), and please share your thoughts in the comments section. I have access to Samsung’s relabeled versions of the *ist DS and K10D, and next time I’ll use them instead. I’ll report back my results here at Brian’s Brain.
Indy Pro
IndyCar
Grand-Am
