B+W 77mm Kaesemann Circular Polarizer with Multi-Resistant Coating – Product Description:
Circular polarizing filters are made for all cameras with beam splitters in the light paths of their TTL exposure meter and with autofocus lenses. Circular polarization has the same pictorial effect as linear polarization, but allows for proper exposure metering and/or autofocus distance settings. The “high-end” polarizing foils of the Käsemann-type filters are neutral in color, they have a higher efficiency than conventional polarizing foils and they are cemented between high-grade plane-parallel optical glass. The resulting sandwich is then precision-polished again to achieve highly accurate plane-parallel surfaces. Subsequently they are edge-sealed to protect the foil against humidity. Discriminating photographers regard the B+W Käsemann-Type Polarizing Filter to be the very best of all polarizing filters. They are well suited for applications that require the highest possible imaging quality, especially with high-speed telephoto lenses and apochromatic lenses.
|Product Features :
B+W 77mm Kaesemann Circular Polarizer with Multi-Resistant Coating – Review:
HIGH QUALITY POLARIZING FILTER!
Paired this polarizing filter to my Canon 17-40mm F/4L lens on a Rebel XT (1.6x Crop) and it works great. As you turn the filter the change in the image through the viewfinder is night and day. Creates a nice blue sky and gives more “pop” and contrast to clouds. Also eliminates reflections from plant leaves (you really have to see it for yourself!) to create a nicely saturated green only a filter of this type can produce. Must have for any outdoor photographer.
The “Kasemann” designation from my research stands for B+W’s edge sealing of the glass. This is to prevent humidity and other types of weather from separating the foils inside. Over time regular polarizers can become hazy, etc. from that very problem. Just buy this one to keep for life instead of spending 50 dollars every few years. The filter frame is made out of brass, unlike other filters that are made of aluminum. This aids with smooth operation and eliminates binding.
I’m not entirely sure however if the wide angle of the 17-40mm needs a “slim” glass element (some say use of a regular polarizer with an ultra wide angle can cause an uneven polarization effect, however they are not clear if its on a crop body like the Rebel XT I’m using wit with). Some say a slim filter isn’t needed, some do. I will have to do more outdoor shooting at the widest focal length to find out. Even so, B+W also produces a slim Kasemann version of this filter as well. From what i’ve seen though, vignetting is not a problem with the 17-40mm + this filter on a crop body such as the Rebel XT.
NOTE: I have also read that the way B+W produces the glass/foils will cause a “ripple” reflection effect in the glass when viewed at certain angles. This is true from what i’ve seen with my filter. looking at the filter from an angle and using a desk lamp, one can see the surface of the filter is not completely smooth. B+W has stated this does not affect the quality of the pictures in any way. Perhaps this may have led the other reviewer to believe that this filter scratches easy. The MRC they use is supposed to be very good.
In any case, a 77mm is the perfect size, as many Canon lenses use the 77mm thread such as the 70-200mm F/2.8L, the 24-105mm F/4L, and more. Plus you can always use “step up” rings with your smaller lenses.