Polarizer filters and DSLR's?

[ElCapitan]

I fancy myself as an outdoor and nature photographer. I love photographing the outdoors, all nature, and wildlife. I do not use a polarizing filter, and I have gotten some amazing shots without one. At the same time, there are some times that I feel a shot would have been far better if I did have one. I have heard the polarizing filters aren't needed when it comes to digital, but I have heard several people say that it does help in digital a great deal.

I am young and still learning, but would love to make my career in shooting outdoor/landscape photography, and I will be going to the Outside Exposure 2010 photography workshop in Santa Fe in October. What I would like to know is, would it be wise to invest in a polarizing filter just to have. In the early or later afternoon light I know it shouldn't be needed, but if for some reason I am somewhere in mid day light and find the perfect shot, would a polarizing filter help much? Thanks for any advice.

[OsmosisStudios]

Invest in a GOOD circular polarizer. Keep it with you and use it if you think it might be a good idea. Its as simple as that, really.

[RecurrentNerve]

There's no reason why digital photography shouldn't benefit from a polariser any less than film photography. They help add depth to skies, brighten greenery, remove reflections from glossy subjects, lots of things. Considering they're relatively cheap, they're a handy thing to have.

Here's a shot I took a while back; note how there's a nice gradient to the sky. Believe me, while it's possible to get a similar result in PP, it's a lot harder to get it looking natural.

[LeeR]

A polarizer is a tool just like anything else in a phtographer's bag. As a matter of fact, it is a very powerful tool and most landscape photographers who know how to use them would not leave home without it. However, to be effective you need to understand how they work.
There is a band of polarized light that forms a huge circle at roughly a right angles from the sun. That means that at high noon, with the sun directly overhead, the band is along the horizon line. As the sun progresses, the band slowly tilts up until it is directly overhead when the sun sets. With a polarizing filter you can turn it one way to allow all of this light into your shot, or turn it 90 degrees to eliminate it,with subtle shades of difference in between. This can add great drama to your image as it darkens the sky, but not the clouds, the plants or the landscape. More than once I have found this to be the difference between an image I was proud of and a big disappointment.
Polarizers also have the effect of minimizing reflections on most surfaces except metals. That means that if you are taking a picture of a car in direct sunlight it will help minimize the reflection off the paint and glass but not the chrome bumper. It will also minimize glare off the suface of the water allowing you to see what is in the water. It is also used in photographing works of art where you want to keep glare to a minimum. That gets a bit technical so I won't go into it here, but suffice it to say, this is one very handy tool to have. Mine stays on the front of my lenses when I am shooting outdoors and I make sure my sunglasses are polarized so I will know if a scene will benefit from the use of the filter.
Finally, Osmo is right, you need a circular polarizer. Some digital camera meters are fooled by the old standard polarizers, but the new circular type will give you accurate readings. Can you get great images without one? Certainly, but once you learn to use one correctly you'll wonder how you made it without one.

[Michael_2010]

The following is probably a good example of overusing the circular polarizer. It was taken at the end of February in the early afternoon and it really did a number on that blue sky. I wanted the strong color contrast between the flowers and the sky, but this probably went a little too far.

[wildbird]

I have one on my lens all the time, except at night usually. Even then if it is a long exposure I will leave it on. Best on water though as you can either see under the water, or have reflections. Basically get one and see what it is like!

[Michael_2010]

I used to keep one on my lens all the time too, then I learned it was the cause of refraction light spotting up a capture. Now I take off all filters when shooting directly into the sun, morning or evening.

Back in the days of old, I had a circular polarizer for my 35mm SLR. It had a nice little handle mounted on the side of the adjustment ring. Made it easy to adjust the filter while looking through the viewfinder. Now it is difficult to get my fingers on it and not mess with the focus ring. Add a lens hood and it really gets hard to make adjustments on the fly. Does anyone still make a Polarizer like that these days?

[RecurrentNerve]

They sure do, a British company called Hama have lots of them, see here.

[kencaleno]

There is some confusion on whether to use circular polarizers, or linear ones-they are both circular in shape but they polarize the light passing through them in different ways, You may have read that linear polarizers interfere with auto-focus systems, but as the following explains, the effect is negligable.

The problem is that the percentage of light that is reflected to the focus screen can vary slightly depending on its polarization. Since most cameras meter off of the focus screen image, that can have a small effect on the metering.

Beam-splitters reflect a different percentage of the incoming light depending on the polarization of that light. With a linear polarizer, the light reaching the beam-splitter (viewing mirror) is still polarized, and the direction of the polarization depends on how you have the filter adjusted.

So you see the problem: adjusting the linear polarizing filter will change the percentage of light reflected to the view screen, which in turn will affect the in-camera metering.

But! The difference in the percentage that gets reflected is fairly low for beam-splitters built using an aluminium reflective coating, which is pretty much every SLR or DSLR beam-splitter ever made. It's probably less than 1/3 stop in most cases. Most people will never notice this difference.

[OsmosisStudios]

Originally Posted by kencaleno

You may have read that linear polarizers interfere with auto-focus systems, but as the following explains, the effect is negligable.

Have you tried both kinds of polarizers? Negligible is not the word I would use. Not by a longshot.