The first filter to buy is obviously a UV Filter…. for two main reasons. Firstly they block UV … and secondly they are a great sacrificial part of the lens. Scratch the filter and you’re up for $50-100. Scratch the lens on the other hand… Also the filter will break first if you drop your camera, the lens tends to hit the ground first and the filter takes the shock and breaks.
But back to Polarisers…. Ever wondered how people get those amazing travel shots where the sky is a deep blue and the water a stunning green? And yet every photo you take is all washed out and even overblown?
Like this shot perhaps…
The only difference between the above shot and this one is the Circular Polariser that was on the camera.
Now as you can see, this shot is a lot richer in its tones and colour. I should have shot the second shot a bit slower (to pull in a bit more light to compensate for the filter) but I took these shots to show the difference between with and without the filter. You will also notice that the filter has cut down dramatically on the reflection in the water showing the rocks just below the surface.
Settings for both shots were:
Camera: Nikon D90
Lens: Tokina 11-16mm F2.8
Exposure: 0.003 sec (1/320)
Focal Length: 13 mm
ISO Speed: 200
Exposure Program: Manual
Some people say don’t use Polarisers on really wide angle lenses like my Tokina 11-16mm. Or you get an effect like below. Now see, I liked the effect in this image… the dark banding across the sky helps weight the image to the side of the tower and results in a more dramatic effect. But one thing it does mean is that stitching a panorama can be nigh impossible (due to the colour banding across each shot). You could tweak the filter for each frame comparing it to the last (using a tripod to keep the camera steady).
One thing to watch for in really wide lenses however is Vignetting (darkening in the corners of your shot, which is almost black). The Tokina 11-16mm at 11mm with a Polariser on is so wide and the filter so thick, that vignetting does show up in the corners of the shot. In most cases here I ended up shooting at 12mm or higher – just to keep the filter out of the shot. Sure I could crop out the vignetting later but pushing the lens that little bit saved me a lot of work in Lightroom later. (Best clicked through to see the large versions on Flickr)
The other issue is not touching the damned filter. It has taken me a while to get used to spinning the filter to the correct level or polarisation without touching the filter itself. Also watch for lens hoods… most of them even petal shaped hoods make it very tricking to reach the filter to move it. Now my fingers are not big mens hands either, so you may need to work out which works best for your lens and hood combination. The Tokina for example I just don’t bother with the hood when I have the filter on, the Sigma 18-200mm that I have is o.k – now that I have got used to it.
So if you are thinking about ever shooting water, sky, or the big landscape that is Australia go out and get yourself one of these filters now, in fact get more than one if you have more than one lens… you will not regret it for a minute and will be wondering why they hell you didn’t get one earlier.
For more info read the Wikipedia link on Polarising Filters