# Polarising filter Ski Photography



## sunlou (Mar 23, 2011)

Hello all,

I have to shoot a Ski competition this coming week-end and I have been wanting to get a polarizing filter for a while now.

Will it prove usefull for That venue?

Also I have a low quality tripod. should I take the skier on a tripod or handheld could do the trick... 

lens sigma 70-300 3.5-5.6 not stabalised...

The skiers are 13 years old so their fast but not crazy fast


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## KmH (Mar 23, 2011)

Circular polarizing filters are most effective when the Sun is no more than 30° above the horizon and at a 90° angle to the lens axis.

When outside those limits a polarizing filter will still add some saturation to greens and blues. How much and where in the image the saturation will be added will vary by the time of day and the angle of the Sun to the lens axis.

In other words, part of a blue sky on one side of the photo is likely to be more saturated than on the other side of the photo.

You will, by necessity, be panning handheld, so the subjects won't be moving much relative to the image sensor, but the backgrounds should be nicely blurred. Good camera holding (cradle the lens in your left hand, elbows in against your torso) and panning technique (most of your weight on your front foot, turn at the waist) will be helpful (essentially you make your body a tripod).

Snow, being so white, will fool your camera's light meter. The camera light meter is calibrated to a shade of 12% to 18% gray. If you don't compensate, your photos will be underexposed and the snow will also be 12% to 18% gray instead of white.
To counteract that you will want to set your exposure compensation to +0.7 EV to +1.3 EV or so, it depends on the camera lens combo.

The holy grail of action sports photography is faces and emotions, not backs and the back of heads.


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## sunlou (Mar 23, 2011)

Thanks for that.

SO do I buy it for this week end??


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## KmH (Mar 23, 2011)

A circular polarizing (CPL) filter should be included in most photographers camera bag. It's is one of the few filters that cannot be duplicated using image editing software.

A good CPL will cost you about $100. I recommend the B+W brand.


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## Garbz (Mar 24, 2011)

Jeesh a simple yes would do


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## Drake (Mar 24, 2011)

The CPL will give you some nice deep blue skies, BUT:

1. No idea how close you will be to the action, but you will be probably shooting in many directions, changing your angle to the sun very often.
2. To use the CPL you have to rotate the filter to the correct position, which doesn't seem difficult, but:
3. The sigma's front element rotates when you're focusing, and so does the filter with it. Kind of a problem when shooting sport.


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## bikingman (Mar 27, 2011)

> To use the CPL you have to rotate the filter to the correct position



So do you put on the CPL after the camera has focused, which doesn't seem practical, or, do you put on the CPL then let the camera focus and once after adjust the CPL? Or altogether hope for the best?


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## CNCO (Mar 27, 2011)

i think that lens is too slow even for youths. dont forget a grey card. with that much white in the background definitely use a grey card.


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## kashar (Mar 28, 2011)

Can we use fisheye lens for this kind of work ?


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## Drake (Mar 29, 2011)

bikingman said:


> > To use the CPL you have to rotate the filter to the correct position
> 
> 
> 
> So do you put on the CPL after the camera has focused, which doesn't seem practical, or, do you put on the CPL then let the camera focus and once after adjust the CPL? Or altogether hope for the best?


Well, with a CPL I usually focus first, then rotate the filter to a correct position, and then focus once again just to make sure, as it's easy to throw the image out of focus while rotating the filter, especially with cheap lens. This method is not very fast, but fast enough for landscapes. I don't think however that you can shoot sport this way.


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## KVRNut (Mar 29, 2011)

If you purchase a CPL, a little trick I use is to index the maximum polorization point of the filter by putting a couple of tiny drops of CA glue on the exterior of the ring and then putting a drop at the points of least polorization.  As far as using a CPL and auto focus lens is concerned, get a rubber lens hood, screw it on to the CPL and just hold the lens hood when auto focusing.  Yes, it means using a tri-pod but it's a trick that works for me.


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