This type of shot has been fairly well documented on the internet already but let's face it, what hasn't? So what I thought I would do is talk more about the thought process than the actual kit.
Having said that, you do need a certain amount of kit to get these shots but I'll keep it brief.
You could argue that the actual camera is the least important part of the jigsaw here. You don't even need remote triggering, as the built-in timer function would work fine. What you do need is a way to attach your camera securely to the vehicle (whether that be car, motorbike, skateboard, hamster...) and due to the composition I wanted to achieve, for me that meant buying a suction cup mount.
This is basically a big sucker with a standard spigot for mounting accessories: could be a light, a clamp or in my case a Manfrotto Magic Arm. This is an adjustable two-piece arm with the camera mounted on the end. It allows you to adjust the position of the camera and lock it there.
Now, ideally you want three points of fixture to the vehicle - just like using a tripod on the ground - but due to the curvature of the bodywork and the kit I had available this wasn't possible, so I improvised by tensioning the arm against itself. It's just a case of getting the camera as solid as possible so that any bouncing or vibration is kept to a minimum.
So, camera locked down, car clean, road clear... now what? Brief the driver: Go as fast as you can and don't stop!
Driver brief is more likely to be: Keep the wheels straight while I push the car.
Honest! As I said before you want as little shake and wobble as possible and in extreme cases the running of the engine can transmit enough vibration to result in a blurred shot. And another reason for pushing the car is speed. As in, you want the car moving sloooooow!
This is where you have to think. Slow moving car, but you want fast moving shot, so that means an even slower moving shutter, right? But it's daylight and even stopped down to f16 and using ISO 50, you're still getting a light reading of maybe 1/30sec.
- Wait until it gets darker (perfectly viable option, unless you want a daytime shot!)
- Stop down even further if lens allows (but risk reduced image quality for little benefit)
- Neutral Density!
Neutral Density filters are effectively colour neutral tinted glass (or plastic) designed to reduce the amount of light entering the lens without altering any other qualities, resulting in slower shutter speeds or wide apertures depending on your preference. And by stacking them (ie. putting a 1x ND on top of a 2x ND = 3x ND) you can add another layer of control over these ambient light situations.
The shot above was taken at f16 and with a relatively fast (for this technique) shutter speed of 0.5 sec. This was just long enough to get smooth blur on the wheel and road surface whilst being short enough to cancel the effects of bumps in the road. It's a balancing act depending on the conditions you are presented with. Improvise and adapt!
Hope that was interesting, and any questions in the comments section are welcome, either here or over at Stuart Key Photography. Thanks :)