on January 16, 2009
இ Fuzzy Wuzzy's Summary:
ѾѾѾѾѾ Highly recommended with warm fuzzies!
This is the fourth B+W Kaesemann Circular Polarizer that I own. These filters are expensive, but they are worth the extra cost, especially under adverse conditions outdoors where lots of dust, moisture, and temperature changes are prevalent. Unlike B+W's standard circular polarizers, which also have the Multi-Resistant Coating (MRC), these Kaesemann ("encased") filters have a better premium-grade polarizing foil and these are completely edge-sealed for maximum durability under extreme climatic conditions due to changes in temperature and humidity. Since circular polarizers are mainly useful during mid-day outdoor shooting, and because I do a lot of backcountry nature and landscape photography that often involves many hours of daily hiking, I always purchase these B+W Kaesemann filters because they are one of the very best for outdoor shooting in environments ranging from hot and humid rain forests to below-freezing climates while hiking above timberline on a snow-covered mountain.
For mid-day outdoor shooting, this filter will add a huge "WOW!" factor to your photos. In fact, a circular polarizer adds more obvious visual benefits than any other kind of lens filter that you may use. Colors really sparkle, especially on landscape shots where the reds, blues, and greens really pop compared to photographing outside in the mid-day sun without using a circular polarizer. Circular polarizers remove specular reflections caused by sunlight bouncing off of surfaces and they enhance the saturation of colors in your photos. So when colors are being desaturated by some degree of specular reflection, the colors will be enhanced. Not all scenes contain polarized light, but usually your skies will look more blue, the plants will look more green because the foliage is not reflecting light, and flowers will look prettier. Yes, you can increase color saturation using post-processing software. But this circular polarizer naturally adds saturation to the colors. And some people over-saturate the colors during post-processing. Along with getting richer colors in bright sunlight, a circular polarizer can also dramatically filter out the glare and reflections that are bouncing off of water and glass, allowing you to photograph through the water and glass to see more of the stones and fish below the surface of a lake or the objects that are behind a window on a sunny day. This can have a startling effect: for example, without using a CP filter, you may just photograph a reflection of yourself holding the camera pointed at a storefront window because most of the sunlight is causing the window to look like a reflective mirror; using a CP filter, you can photograph all of the items that are actually on display behind the storefront window.
If you want to use a polarizing filter and your SLR camera was purchased during the past 30 years, you should probably use a "circular polarizer" instead of a "linear polarizer". Linear polarizer filters interfere with the beam-splitting metering that is used in most modern SLR cameras, resulting in underexposure.
As with other kinds of lens filters, to save money, you can purchase just one of these polarizing filters that will fit the largest lens you have, and then use step-up rings to mount the same polarizing filter on your smaller lenses. However, since a polarizing filter is frequently used for landscape photography using wide-angle lenses, you may get severe vignetting if you stack multiple step-up rings or if you are using a wide-angle lens. Since I switch between three camera bodies and eight lenses, I just decided that it was better to get separate polarizing filters instead of using step-up rings. My first B+W Kaesemann circular polarizer was a 77mm size, quickly followed by an 82mm purchase. And then I later also purchased a 67mm and finally a 72mm filter for my other lenses.
Unlike other stationary filters that do not move after you screw them onto a lens, a circular polarizer filter has a rotating lens element that filters light to different degrees of polarization. To use a circular polarizer, you just rotate this filter in either direction while looking through the viewfinder until you like what you see as being the best adjustment. If you are using a wide-angle lens and pointing the SLR camera at a landscape scenery shot, as you rotate the CP filter, and depending upon where the sun is, you may see the color of the sky slowly shift from lighter blues to darker blues as you rotate the CP filter. If it is early morning or late afternoon and the sun is at a sharp angle closer to the horizon, you may not see much of a difference as you rotate the filter ring. I personally prefer a light to medium amount of polarization from my CP filter use; this is somewhat analogous to wearing light-tinted or medium-tinted polarizing sunglasses. It is possible to get a deeply-colored dark blue sky by turning the CP filter to maximum polarization, but this can often look too unnatural. There may be situations where I have resort to maximizing polarization because the landscape still has too much glare, such as too many glistening reflections coming from a lake in the foreground of the landscape scene. If you are photographing a snowy landscape in the mid-day sun, you should try photographing both with and without using the CP filter. The CP filter will improve the look of the sky, water, and plants in a snowy landscape, but it may also remove the sparkling glitter effect of the snow, which may either enhance or detract from your photo.
The brass filter mount is very rigid, and unlike some filters with aluminum filter mounts that can bind and be a hassle to screw or unscrew, this B+W Kaesemann CP filter is easy to put on and take off. Because I am sometimes repeatedly going outdoors, indoors, and then outdoors again and wanting to photograph both inside and outside, especially while touring foreign countries (e.g. photograph around the outside of a building using the CP filter and then photograph the inside of the building without the CP filter), I do not like to screw this filter too tightly because I want to be able to quickly put it on and quickly take it off as needed. So I just use a very light amount of torque when I screw the filter on, and I stop turning the threaded filter mount onto the camera lens the moment that it no longer continues to easily screw in. Even though I can rotate this filter clockwise or counterclockwise to adjust the desired effect, I always rotate the filter ring clockwise (which looks like a counterclockwise turn when viewed from the perspective of looking through the viewfinder) as added insurance just in case my fingers are also grabbing the filter mount so that I am not inadvertently unscrewing the filter from the lens if I was to rotate the filter ring counterclockwise. It can be disconcerting to think that you are rotating the filter to adjust the polarization if your fingers accidentally grab the filter mount and you are actually unscrewing the filter from the lens. If you have never used a circular polarizer before, it is worth the time to practice screwing/unscrewing the filter while you are still sitting down at home to get a feel for the amount of torque needed to screw the filter onto a lens and balance that with how easily you can unscrew the filter to quickly take it off.
Compared to cleaning the glass on lenses and other lens filters, I think that something about this B+W filter's "multi-resistant coating" makes it a bit more prone to smearing and streaking when cleaning with fluids. If there is dust on this filter or on my lens, a few good blasts from my Giottos Rocket Air blows the dust off. But if there is more stubborn dirt or fingerprints on this CP filter that requires wiping, the surface of this CP filter can be a bit finicky in getting both sides of the filter totally free of any smears or streaks. To remove fingerprints or dirt, I use a microfiber cloth or lens tissue dampened with isopropyl/rubbing alcohol or water, I lightly wipe in a circular motion, and then I quickly dry off the fluid using another clean cloth or tissue. It seems that some of the fluid can streak if it is left to dry by itself on the surface of the CP filter. Sometimes, I am still left with a few streaks on the filter glass, and if I clean that area again, I can wipe off the streaks. Because these B+W Kaesemann CP filters are more of a hassle to perfectly clean compared to other filters, I really try to avoid getting my fingerprints onto its surface, and I always remove the lens hood when using my fingers to turn the filter ring. Some people leave the lens hood on the lens and reach their fingers down into the hood to turn the CP filter, but that increases the risk of touching the CP filter's surface and getting fingerprints onto it.
If you are using this circular polarizer with a wide-angle lens (e.g. about 25mm to 28mm or wider) or fisheye lens, since the angle of polarization varies continuously with the angle from the sun, and wide-angle and fisheye lenses can cover such a huge field of view, there is a possibility that you may end up with a sky that is unevenly polarized, and the sky will have a strange gradation of colors ranging from dark navy blue to pale light blue. The sky will be the darkest at a 90 degree angle from the direction of the sunlight. When using a lens that covers a very wide angle of view, the direction of the sunlight changes across the scene, resulting in varying degrees of polarization. This transition of sky colors may happen laterally, vertically, or diagonally. If this color banding is very severe, you can sometimes see this uneven polarization through the viewfinder and attenuate the effect somewhat by turning the circular polarizer. But at other times, you may not notice this uneven polarization while looking through the viewfinder. The shifting sky colors may become obvious if you review the photo on the camera's LCD screen, but if you are shooting during mid-day and the LCD screen has a lot of glare, you may still not notice this problem until you look at the photos later on the computer screen. This odd-looking shift of blue colors in the sky can be evened out a bit using some creative post-processing, but this is mainly an issue with wide-angle lenses, and it may become very obvious when using ultra-wide-angle lenses or fisheye lenses.
Also remember that all circular polarizers lose at least one or two stops of light exposure, like using a neutral density filter, and details in shadow areas will be diminished, so you should not use this filter when shooting in conditions of low light, overcast skies, and indoor environments (which would not be helped by this filter anyway).
on July 29, 2008
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.