B+W 66-1066109 67mm 007M MRC Nano Coated Clear Glass Protection Filter - XSPD Mount, Black

I have recently bought my first APS-C DSLR (a Pentax K-X), and I soon realized that I needed a specific protection filter for its lens, especially since I intended to use the camera for some ultra-close up shots, which can be really dangerous for any lens (since you can literally bump into your subject or its surroundings, while looking for the perfect framing, with the actual danger of cracking the precious front surface of the lens...).I already had some old and cheap UV-filters for my 35-mm film camera already, but they were un-coated and totally useless, since digital camera sensors are already protected against UV rays, so these old filters just gave a purple/darker tint to the images shot with the new camera, introducing ugly flares and reflections on every shot including a front-facing direct light source.So, initially I tried to find the cheapest _coated_ protection filter I could find, but soon I realized that most of the cheapest one were either un-coated, or their coating was negligible, according to the opinions of other Amazon buyers. So, in the end I decided to buy this one, even if it costed slightly more than most other ones, due to the good reputation of this brand, and to its specific and peculiar characteristics.1) It is a _german-made_ "digital" filter, designed specifically for digital cameras, so no unwanted and useless "anti-UV" color casts or darker images;2) It includes a _real_ anti-reflective coating, a feature I could verify as soon as I opened its package, by simply looking at the very dim, dark green reflections coming from its front surface (to explain what I mean, try to compare the mirror-like reflections produced by a cheaply-coated or uncoated piece of glass/filter and the dim green or blue reflections produced by good, coated prescription glasses, or simply those produced by any good coated camera lens front glass...)3) It offers what the manufacturer calls XSPD mount, i.e. a _very_ thin mount that only leaves a minimal space between the back surface of the filter and the front surface of the lens, which is very important to avoid catching more reflected light rays between the two of them, and also reduces the total length/weight of the lens, especially if you are going to add more accessories/filters/converters/etc. in front of it;4) It is clearly manufactured in a professional way: it is very sturdy, even if very thin, and the glass does not wobble/rotate at all inside the frame, something that often happens with cheaper filters;5) It is packed in a nice and sturdy case including thick protective padding;6) The threading is incredibly precise, and - even on such a thin ring - it allows to mount more filters/accessories/etc. on the front of the filter. Moreover, there is enough space on the front to allow easily the insertion of a lens cap with springed "hooks" inside the filter;Considering that the price I paid for this filter, when I ordered it, was not excessively higher than the price of many sub-standard, no-quality, uncoated or falsely coated filter available, I consider it a real bargain, even if it just protects the lens and does not improve the image quality in any way: in my opinion, it is definitely preferable to invest a little more in an important accessory like this, rather than sparing a few pounds by choosing cheap ones, and risking to compromise the quality of ALL your shots with horrible reflections, think about it...After all, optics is one of those fields in which cheaper is _never_ better, believe me!

I spend a long time choosing camera equipment. I like the protection offered by a clear filter but the last thing I'm going to do is to compromise the quality of my pictures by putting inferior glass between my lens and the world. Hence I'm prepared to pay a little more for a top quality piece of optical glass. B&W have always made first-rate filters and I recommend them wholeheartedly.

This filter, as you might expect from B+W, is built to a very high standard. The mount is made of brass and the MRC coating on the glass really helps reducing reflections and I did not notice any decrease in image quality. The mount of the filter is very slim so it should not cause vignetting on wide angle lenses. The coating is also supposed to repel dirt and water, though I've yet to see that. All in all, you really get what you pay for and in my opinion, this filter is absolutely worth the price.It's also worth noting that it arrived in a ridiculously big box (25-30 cm cube shaped box!) which is an absolute waste of material since the manufacturer packaging is only about 7x7x1 cm!

B+W make Great Filters, but a word of warning: if you propose using the filter on, for example, a Carl Zeiss OTUS 85mm f1.4 use the F-PRO mount instead.I know the mount thickness should be kept to a minimum in order to prevent vignetting, but I would much prefer a small amount of vignetting than a jammed filter, especially when used with an expensive lens.B+W use Brass to reduce the chances of jamming.Recently, I have found to my cost, there is a risk of jamming with the XS-PRO mounts above 86mm, especially if used with a none brass counterpart, in my case an aluminium screw-in lens hood. The aluminium is prone to “swarf pickup”.I think the problem arises from the fact that Brass and Aluminium have different Linear temperature expansion coefficients; 18-19 vs 21-24 and a combination of creep and thermal cycling cause the surface defects in the machined thread of the aluminium to “dig into” the brass.

use B+W filter more than 25 years, use it with L lenses of Canon, never degrade image quality unlike other filters cheap filters...

For years I have always used "top of the range Hoya" but on upgrading my back-up camera to the Fuji X100 I discovered that I needed a clear glass protection filter and because I had paid so much for the x100 I thought that I would spend a bit extra on a filter. Wow what a difference,once on its almost invisible when looking at the from element of your lens and the brass fittings just move like silk. The one downside of using this type of filter is that unlike the Hoya's you can't really use a plastic lens cap with them for fear of marking the filter. Now I made a soft bag type cover for the x100 (best every ready case ever) to get around this problem and also because I hate conventional every ready cases (because they are never read) and the fact that the one made by Fuji for the x100 will not fir the camera if fitted with a protection filter (which it needs). The other thing which I noticed was that with the NANO Coating on the B&W, dust and bits were a lot less of a problem that with my Hoya's. I was so impressed with this observation that I went out and bought further B & W clear glass filters for all my Nikon Lenses and which to get around the not being able (or wanting) to use the plastic lens cap I store them all in Micro-fiber Pouches which you can either make yourself (or get the lady in your life to make) .Alternatively you could just buy Giottos Micro-fiber Cleaning Pouches as I did from the USA ( outdoorphotogear.com) at about $9 each (£6) and provided you limit yourself to under about £18 then there are not UK import taxes and Outdoorgear also have very reasonable postage and packaging rates.