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View Full Version : Which Polariser?


Willom
30th November 2010, 04:00 PM
Being not far from Christmas I am starting to consider what acessories I might need for my camera. I have done a bit of research in to polarising filters and I feel I could do with one. The trouble with research is that it often throws up more questions than it solves. I didn't realise that they came in two flavours, linear and circular. Which one is best for the E-510? Or does it depend on how I want my pictures to turn out?

As ever any advice will be greatly appreciated.

Will

Alan Clogwyn
30th November 2010, 04:04 PM
I believe that linear has a stronger effect but hinders auto focus (but that monly be with live view?), whereas a Circular one will autofocus fine but the effect is not so strong, or so I'm led to believe.

Wally
30th November 2010, 04:42 PM
As you've rightly guessed, there are two types of polarizing filters generally available, linear and circular. With the exception of how they interact with some autofocus and metering mechanisms, they have exactly the same effect photographically.

Linear Polarizers:
The metering and auto-focus sensors in certain cameras, including virtually all auto-focus SLR's will not work properly with linear polarizers because the beam splitters used to split off the light for focusing and metering are polarization-dependent.

Circular polarizers:
Include a linear polarizer on the front, which selects one polarization of light while rejecting another, followed by a wave plate , which converts the selected polarization to circularly polarized light inside the camera, which works with ALL types of cameras, because mirrors and beam-splitters split circularly polarized light the same way they split unpolarized light.

What can a polarizing filter do for you? A polarizing filter has two applications in photography: it reduces reflections from some surfaces, and it can darken the sky.

The benefits of polarizing filters are largely unaffected by the move to digital media, while software can simulate many other types of filter, a photograph does not record the degree of polarization, so the optical effects of controlling polarization at the time of exposure cannot be replicated in software.

Wreckdiver
30th November 2010, 04:55 PM
Will, you should go for a circular polariser. Either get a round one that screws on to the front of the lens (diameter as shown on the front of the lens) or, if you plan to get ND grads or NDs at a later date, go for a rectangular system like the Cokin system. The latter way you buy the holder and add different types of filter as you go, you only need to buy a new adapter mounting ring for each lens size (cheaper in the long run).

If you just have one or two different diameter lenses then just get the screw on types, one for each lens diameter.

Edit: Try these: Circular Polarisers (http://www.warehouseexpress.com/search/Default.aspx?q=hoya%20circular%20polarise)

Steve

Willom
8th December 2010, 10:00 PM
Guys,

thank you for your advice. I'll ask Father Christmas for a circular polariser.

Will

benvendetta
8th December 2010, 10:10 PM
Circular. I have a reasonable priced Hama which is fine for the odd times I use it. I seem to get natural polarisation with my ZD lenses.