I was recently lucky enough to be asked by Microsoft to film a road test for their MSN cars section. The location was Goodwood race circuit. The cars were a Porche 911 turbo and a Audi R8 V10 (both convertibles)...and the weather? Wet, windy and raining all day - the perfect weather for a convertible shoot!
Goodwood race course itself was a great location to shoot at, as it is steeped in motor racing history. It was somewhat odd to be told that we need to be fairly quiet with the cars as the engines might upset the neighbours. Also we had a speed restriction in certain parts of the track. Its was a bit of an oxymoron to have a turbo and a V10 engine and expect them to be quiet and ironic to have a speed restriction on a race track!
This was the first test shoot with the new Canon 7D rigged for film and so I was quite excited to see how it would perform under extreme conditions.
Usually when filming at speed you get a lot of vibration which makes the images distort. On this particular shoot the 7D was fine and I was impressed by how the image was not affected when I used the stabiliser on the zoom lens. If you are using prime lenses with no stabiliser then expect some vibration. More recently I shot a bonnet mount on the new Audi A4 and I used a nice 24mm Carl Zeiss 2.8f prime lens to get a nice depth of field, but the vibration from the engine alone was enough to cause problems with the image. There have been lots of reports about the HDSLRs having a 'jelly' effect on the image sensor when the camera is shaken about and this was certainly the case with the A4 shoot. Therefore I would recommend that you sacrifice the depth of field and use a lens with a built in stabiliser.
Overall the 7D performed way above my expectations and you only really notice that when you are looking at the rushes. It allowed some great 50fps footage to be shot and again this helps in the edit to slow down any bounce. In fact the only problem I really had was the lousy weather.
When you are shooting low angle out the back of a moving vehicle at speed and on a wet surface, you have a very limited amount of time before your lens is covered in gunk and water. So you are constantly wasting time cleaning the camera and the lens. A few solutions to this are to drive slower or move to a country where it doesn't rain for ten months of the year!
The only other thing that the 7D needs is a monitor. The viewfinder at the back is a great feature and as it has a live mode it allows you to point and see what you are shooting. However, the viewfinder is only a guide and while the images may look sharp on it, once you get it back to the studio, they may have been soft - and that's upsetting!
Of course the viewfinder is on the back of the camera so if you have the camera out the back of a moving car, then your head has to physically be behind it to see it, which can be impossible or even dangerous in some situations.
The solution to all this is an external monitor like the Marshall V-LCD651ST-HDMI. It has a 1024x768 resolution and can easily connect to the hot shoe of the Canon that allows it to be positioned in any direction. But more importantly it has an in-focus filter that actually allows you to see when your image is in focus or soft. It also has an exposure filter that allows you to see if the subject is correctly exposed. It has great playback in a higher res than the viewfinder with an anti reflection screen. In short this should be the answer to most of the problems I came across on the shoot...that and a nice spell of sun!