Shooting Cars – What is a Polarising Filter and why do I need one?
When you’re shooting cars for whatever reason, whether they are for sale or especially for a magazine feature, you really need to manage the reflections.
Cars can be a pain to shoot as they have lots of curves and flat panels, these cause reflections and sometimes you’re going to want to get rid of them, especially if there are things in the them do don’t want in your image. The easiest was to achieve a reflection free surface is to either make sure the car hasn’t been polished, and that’s not really an option is it, or to add a polarising filter to the front of your lens. The majority of DSLR lenses have a threaded end so that you can add your filters easily, I always add a good quality UV filter to all my lenses, it not only helps to protect it from ultra-violet light but in the event of an accident it’ll be the replaceable filter that will take the brunt of any impact rather than the front of the lens.
There are two types of polarising filter, a linear version and a circular type, or CPL as it’s known. Unsurprisingly the linear version only allows vertical or horizontal light to pass through when its rotated while the CPL has a dichroic layer, sometimes called a pola foil, that is sandwiched between two layers of glass. If you’re interested in the science then you’ll have to Google it as I’m not going to go into that here.
Some photographers use their polarising filters to improve their landscape images, but I use mine for automotive photography and hate to see a magazine feature where one has not been used. Below you can clearly see the reflections on the widescreen in the first shot and the ones on the side in the second. The camera is securely placed on a tripod so as to eliminate as much movement in the images as possible and then they are merged in post-production, I also took the opportunity to move my off camera flash. Until recently, I had just one 600 watt portable flash, I found one for a decent price so decided to upgrade and so whilst there might be a little more work on site, there’s be less to do later. I really try to get the best shot possible in camera so that I’m not spending too much time making adjustments once I’m back at my desk, I’m always on the lookout for distractions in the image like unwanted litter even down to blades of grass if my camera is shooting from the floor.
Of course some colours of vehicle, and paint finishes, are easier to set up in camera. In an ideal world the subject should be at 90 degrees to the sun to get the best results. Of course in the real world it’s not always that easy and the backdrop, like this track, dictated as to where the photo was going to be taken. Obviously you get what you pay for and an expensive filter will do a much better job than a cheap one, but with everything, I always think that if you buy the best you can afford then you can’t go wrong. Plus it’s always good to have a place to go and a target to achieve.