A little advice needed...

[Acathla]

Hey all,

I've been lurking around here for a while, but this is my first actual post... please be gentle!

I've recently upgraded my camera body, and headed out to Brands Hatch to give her a little road test. I've been here many times, and, generally speaking, my panning technique is normally pretty good. However, while viewing my shots from this trip, I noticed that in a lot of the shots I'm only getting half of the car in focus. I used my normal settings (AI Servo; central focus point; shutter priority; ISO 100), and I can't say I've ever encountered this before. Here's what I mean:





The Porsche only has the front in focus, and the Focus (no pun intended...) only has the back in focus. I think these were at around f/14, so I can't see how it's a DOF issue. Are my settings off, or am I just out of practice with my panning?

My only other option that I can see, is that I had my lens IS switched on... Could this be fooling the camera somehow?

Any help would be very much appreciated!

 

[Fireproof Creative]

Parallax due to shutter speed and relative angle would be my guess. Up the shutter speed and you'll get more of the car area in focus or change position so you are perpendicular to the car when releasing the shutter.

If a car is coming towards you at an angle or cornering, the front and back are moving at different speeds relative to the camera, so the longer your shutter stays open, the more relative blur you will see at either side of your focal point. The other way to counteract this effect is to maintain a set distance from the subject and match it's speed... Thus a rig shot

 

[Acathla]

If a car is coming towards you at an angle or cornering the front and back are moving at different speeds relative to the camera.

Ah, that makes sense! I was shooting between 1/40 and 1/60 to get as much background blur as I could... next time I'll up the shutter speed a bit and see if that does the trick! Thanks Jonathan.