Have you experienced a Polarizing filter? If you have not, I seriously recommend trying one today.
Yesterday I was contemplating stuff … you know, looking through my memory bank of photographic experiences, when I suddenly stumbled upon a gem! The first time I looked through a telephoto lens with a polarizing filter at the other end … MAGIC! The world was different; the sky was a darker shade of blue, the leaves were a richer green and wonder of wonders, the lake surface I was looking at was clear! That was my first Pola-Magic moment.
The second was a bit more ‘impersonal.’ It didn’t happen to me in person. But that didn’t take away any of the magic. It was on TV. Discovery channel, I believe, and I was watching a program about wildlife. The image on the screen was that of a dolphin (or maybe it was a shark or a killer-whale, I got lost in the magic and forgot what exactly they were following) and it seemed like it was being photographed by some new kind of underwater camera until suddenly it broke the surface to breathe and I noticed that splashes of white foam broke to the sides of the animal. It was magic!
Here I was, thinking for all this time that the animal was being followed by an under-water camera when in fact it was being shot by a cameraman in the air, suspended a couple of hundred feet above the animal (yes, I know its stupid not to recognise the angle of the shot, but did I mention Magic?). The photographers themselves were talking about the magic of the moment, and then the magic was revealed. They were using a polarizing filter on the camera. My second Pola-Magic moment.
Now, there’s something else that I have to mention about polarizing filters, but that involves a bit of a technical discussion about how polarising filters work in the first place. I assure you, it will be to the point and will help you with your experiments with Polarizing filters.
When light from the sun strikes an object, it is naturally polarized. All the rays come from the same source, and as a result the waves are oscillating along the same axis. Now, when they strike an object, the rays scatter, shifting the plane of the waves and scattering light. Polarizing filters work by allowing only light waves that are oscillating on one particular plane to pass through. This means that reflections are naturally removed, because reflections are formed by light rays reflecting off a different surface – and therefore, have a different light ‘source’ – and most likely have a different axis of oscillation.
How to use them
Polarizing filters come in two types… Linear and Circular. The linear kind was given up with the advent of auto-focus cameras because of the way that the AF in the cameras worked. The circular polarizer is designed to work with AF mechanisms and still let you have great Pola-Magic moments. They’re neutral filters in the sense that they don’t add any colouring to the image. When used correctly, they increase the saturation and vividness of the colours in your frame, clouds in the sky are better defined, leaves are a richer green and just about everything looks nicer.
Here are some tips to help you when using a polarizing filter:
- A polarizing filter is a very interactive one. It’s not one that you just screw on and forget about. You need to keep adjusting it to get the best results.
- Polarizing filters don’t work very well with wide-angle lenses. They tend to darken only certain parts of the sky and leave other parts bright. This could leave you with a patchy sky. Not a good thing, unless you like it that way.
- Polarizing filters will not remove reflections from mirrors or reduce reflections on metallic surfaces.
- A polarizing filter is made of two parts. A screw-in mount to attach it to your lens, and a filter housing that is firmly – yet freely turning – attached to the screw-in mount.
- When using the polarizing filter, first compose the frame as you want it.
- Turn the filter once you’ve composed the frame until you get the desired polarizing effect. It is most effective at 90 degree angle to the sun.
- Remember that a polarizing filter typically reduces the amount of light that goes through it by around two f-stops. This makes it a bad idea to use it in dimly lit situations. It also means that if you’re using a camera that does not have Through The Lens metering (TTL), you’ll have to open up by roughly two f-stops. This is a number that you’ll have to arrive at by trial and error.
Find Polarizing filters on Amazon.com. Or, if you have one in your bag, get it out and start shooting!
Do you have some other tips about polarising filters that you would like to share? Do leave a comment or mail me.