Monday, 6 February 2012

Using a polariser and neutral density filter together

There has been much written on the use of polariser filters and neutral density filters (ND).

On a shoot the other day I had a classic example of how they work so well together, of course there is more than one scenario, however I thought these two images demonstrated it perfectly.

Why use them together? Well they do two different 'things' and combined those two 'things' can allow you the opportunity to control light and therefore capture an image impossible without them. Let's face it, our cameras can only do so much with the lighting situation we present them with.

After the recent rains in south-east Queensland a friend of mine that some of you have met, Linden and I took off to photograph his jeep crossing the 14 Condamine Crossing four wheel drive road. We knew the crossings would be over and flowing at a good rate and hopefully perfect for an image I had in mind. 

I was also glad he informed me before the first crossing that the jeep had a bung or two missing in the floor so we should ensure our camera bags were up off the floor. The water slowly lapped at our doors, seeped in and the muffler gurgled and smoked on many of the crossings, however the whole day enabled us to have a play with creating long exposures in the middle of the day.

In the first image below only a ND filter was used. The water is slowed to a milky wash but the car's windscreen and windows and other highlights in areas such as the rocks, foliage and sky are over exposed. By placing a polariser on as in image number 2, the reflections are reduced, contrast and saturation are increased to what our eye sees of the scene. The result, I think you would have to agree, is the second image is a much more appealing image.

One of the main problems that can occur from stacking filters like this is vignetting. If you get some make sure you frame your image to allow for some cropping preferably in an aspect ratio suitable for your camera.

When I use my ND fitter and polariser together I always place my polariser closest to my lens. I polarise the scene, pre focus on my subject then turn the auto focus off. I then carefully place my ND filter on the top of my polariser making sure no part of my lens changes position, meter read through the lens and that is my starting point for my exposure and its usually pretty close but I do bracket and of course, I always shoot in RAW and jpeg.

The presumption that the polariser filter does nothing unless the sun is at the right angle I have to say I find a double edged sword as it depends on what you want. If you have a half decent polariser (some are much better than others) in your kit try combining it with a ND. You may be amazed at the final result. They are a fabulous combination when used together for so many scenarios from landscapes and seascapes to busy cathedrals, streets and temples where you can make the hordes of people disappear and best of all they are such easy tools to carry in our kit.

Image 1.

 Image 2.
Both shot on Nikon D700 with a 17-35mm lens set at 24mm

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