What polarizing filters do for you is pretty much explained by the sample shot on the : Amazon web page
. Just click on the rightmost image at the bottom of that page to change view.
1. It makes water or other reflective surfaces translucent
2. It generally saturates the colors under bright sunlight, where e.g. leaves reflect much blue light from the sky. The pol-filter filters out the reflected blue light and the leaves become their more natural green.
Watch out: you have to turn the filter to a certain angle to get the effect!
As to the different offers from Amazon: The set contains the cheapest fol-filter from Hoya, the other one is the highest quality pol-filter from Hoya.
What's the difference in quality? The cheaper one seems to have a broader rim and is therefore more likely to cause vignetting at wide angle lenses and its coating is certainly not of the same quality. A better coating results in less ghosting and flare and a higher contrast. You have to remember that a modern lens already contains some 11-17 elements many of them with reflective surfaces where the light entering the lens bounces back and forth without going the proper way through the lens. If you add another layer of glass through a filter, you risk more reflections and stray-light.
: The price for the better filter is certainly a bit over the top. I got mine for around 55EUR.
Two further remarks:
1. In general, Hoya is said to build good quality products - and my filter certainly is...
2. You should never buy a "linear" pol-filter! Always stick to the "circular" type!!
Also looky here: http://www.cameralabs.com/forum/viewtopic.php?t=401
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews
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