Motion in Motorsport - Part II
31/03/12We've described our technique for capturing motion in motorpsort previously, and particularly about panning, and how to shoot through the ubiquitous wire fence found at most motorpsort venues.
Motion in Motorsport Part 1
One of the techniques to allow for slow shutter speed down to 1/80 to 1/100 in bright sunlight, while shooting wide open (allowing shallow DOF to render the wire fence invisible) is to use ND filters. These are easily obtained and fitted to standard zoom lens, and this is what we have used in the past for the Canon 100-400 L and the 70-200 f2.8 IS. Both of these lens utilise 77mm filter threads. We have used 1- 3 stop ND filters for this purpose.
For 2012 however, we were shooting with a 300 f2.8L IS and could not source the drop in ND filters required which were on backorder. As a result we had some trepidation as to whether we could take suitable panning images if the light was too bright.
As luck would have it, the Australian GP weekend in Melbourne this year was blessed with fine weather and the track was bathed in sunshine for 3 days.
The first thing we did on arrival was to search for shade. Not for us, but for parts of the track where trees provided shade on the wire fence we were shooting through. This helps make the fence much less visible.
Depth of Field depends on many factors, including aperture and focal length. With experimentation, we found that a 300mm f2.8 IS lens with a 1.4x III extender and thus 420mm @ f4, gave a narrower DOF than a 300mm @ f2.8. This was on a Canon 1d4 with a 1.3 crop factor. As a result the wire fence was les obvious with the former setup.
In addition to finding shade, we needed sites around the track that we could pan successfully. Shooting static images are easy. Get as close to the fence as possible, shoot wide open, adjust the shutter speed to whatever your meter suggests and then shoot away - although we generally underexpose by 1/3 to 2/3 stop.
For panning images though, you have to choose your position more carefully. It's fairly difficult to get a high rate of keepable images attempting panning shots down the middle of the main straight while the F1 cars are doing 300 km/h.
We generally choose a slow corner where we can track the cars as they brake, and then pan as they accelerate out of a corner. Ideally the position should enable you to get close to the fence, but the corner should be a good distance away so a 300mm or 400mm lens can frame the car appropriately. If the corner is too close, the 400mm lens will be too long, and if you do use a shorter lens, the DOF will be wider, and thus the fence will become more obvious.
We have found Corners 2, 5, 9 and 14 to be ideal for this at Albert Park.
However due to lack of drop in ND filters for the 300mm F2.8 IS, on a bright day, we were unable to get down to the shutter speeds of 1/80 to 1/100, while shooting at F4 with the 1.4x III extender, despite an ISO 50. So we upped the aperture to f7.1.
This image of a Formula Ford we feel shows acceptable results of panning, but there are parts of the wire fence still visible. However the pan helps blend the fence into the background. This was taken at Turn 14.
This pan of a Group C Commodore was taken when there was temporary cloud cover, which allowed a wider aperture, and with less sun on the fence. The fence is therefore much less obvious. This image was taken at Turn 5.
This pan of Alan Moffat's Sierra Cosworth illustrates what happens if the track is close to your shooting position. You can still pan, but with a long lens, only a portion of the car is visible. However, the finer details of the car are better appreciated. This was taken at Turn 3.
Finally, it's difficult to get the perfect conditions to all come together at once, and as a photographer, sometimes you just take what you can get. We had positions ourselves just past Turn 9, found a tree which shaded the fence and got our gear ready for the final F1 practice on the Saturday. However, by the time the F1 cars got going, the shade had moved, and the appropriate spots were already taken. Nevertheless, we shot away, and the images were still accpetable even though the fence is noticeable.
Next time we will bring a sundial to help predict the shadows.