Polarizing filters

January 05, 2011

Are probably the most widely used filter in landscape and nature photography. So today, I thought I would mention a little about them, as I just received a replacement for my Nikon 77mm Circular Polarizer II (which I unfortunately dropped and smashed on a rock) and, at approximately $200 dollars a pop, they don't come particularly cheap.

A polarizing filter does a variety of things, but the most beneficial aspects for me, are it's ability to improve skies dramatically and block out a lot of reflective glare from surfaces such as water and glass. They also help create a better overall colour saturation and mid tone luminosity balance across the entire range. These three things alone justify using one whenever taking outdoor shots on a bright sunny day, photographing in and around water scenes (ie: boats, harbours, ocean, swimming pools) plus anything that involves a shiny type surface, such as windows, outdoor signs, metalic surfaces, vehicles, etc.

The best thing about the polarizer is that it's so easy to use. What you see is what you get. Simply look through the viewfinder and rotate the cylinder ring (with your finger) until you see the type of effect that you want - press the shutter and you are done - that's it.

This afternoon was another gorgeous, bright, sunny day here on the southern tip of Vancouver Island, so with my new replacement polarizer in hand, I thought I'd go out and take a few test shots, just to make sure that this one is also up to scratch.

Here is a comparison split shot with the left image showing the polarizer set to maximum effect, and the right side with it rotated to create a minimum result. This is how all those famous nature photographers capture the wonderful, rich, intense, postcard quality, deep blue skies. So the next time you see one of those amazing magazine images of Santorini (Greece) with that fantastic, typical Mediterranean sky colour...you will know exactly what they used to get it. It's really no secret, they use a polarizer.

Please note. One thing a polarizer will not do...is turn completely grey, dull, overcast skies into great looking blue ones. IF you need to actually 'replace' the sky to that extent...then Photoshop is definitely your best friend.

The most polarization is obtained when the lens is at a 90 degree angle form the sun, altho it also seems to work very well for me when I have my back turned toward it. The example photo here was taken with the sun almost right behind me which would represent a full 180 degrees.

Click on the thumbnail to view it at a much larger size.

I'm not going to go into all the scientific stuff here, simply because there is a lot of information available on the web, if you need to find out about the physics of polarization, etc.

As I mentioned above, another great benefit is it's ability to reduce reflective glare with regard to glass surfaces, thus allowing one to actually see "right through" an object, window or whatever.

This shot of a blown-glass hummingbird feeder clearly demonstrates this.

Again, this photograph was taken on a very sunny, bright, summer afternoon with a lot of potential glare bouncing off the glass bowl. With the use of the polarizer it not only cuts down the actual sun reflection itself, but also allows us to clearly see through the liquid and the objects within. Plus, the overall colour saturation is intensified, creating a very pleasing end result.

The only downside for me (as a purist) is perhaps the psychological dilemma. Is using a polarizer cheating? Are the photos I take now suddenly fake or unrealistically enhanced? Well, yes and no. The true colours and balance are really there, they DO exist in nature. However, the human visual system cannot polarize by itself and therefore we need a little technical assistance in the filtering department. I guess it's a moral compromise that I'm willing to live with.

With regard to my outdoor flower images some folks do claim that polarizers can help improve floral photography by intensifying the colour of foilage, leaves, and also help reduce things like blue skylight reflection response coming from berries or small blooms, etc. Well, I have experimented with one for a number of years and I'm not convinced that they actually offer any true benefit. In fact, I often find that the polarizer will change the "colour hue" of the bloom and create a different (ie: unnatural) looking tone. My Nikon Polarizer II filter works great for things like skies, water, glass and other outdoor or landscape type situations, but I've chosen not to use it with any of my flower shots, simply because I have not liked the effect it produces. However, as I only shoot on a bright, but completely cloudy day, I don't find reflections or glare to be an issue

Oh, and BTW - just one more thing...

These new circular filters are really thin (the Nikon polarizer is just 4mm thick) so extra care is definitely required when using them. One needs to screw it on tight enough (but not too hard that it will wreck your lens thread) so that it won't 'unscrew' itself when being rotated. As the outer ring is SO close to the inner fixed part it's almost impossible not to turn the whole unit together as one turns it back & forth.

Just double check (after every few twists) that you aren't in fact unscrewing the whole thing. Otherwise, as I recently experienced - the filter can suddenly fly right off the lens and smash into pieces on the ground.

Thanks for reading.

KEV