K&F Concept 55mm Circular Polarizer Filter with Lens Cap Optical Glass Ultra Slim 18 Multi-Layer Coatings Polarizing Filter for Camera Lens (K-Series)

I experienced great customer support from K&F, but this is only one reason to buy, as I explain below.This budget priced polarizing filter is a great choice for your lens. It is multi coated to help with filter to lens reflections, it's scratch resistant, but not water proof. The filter is well made and feels good in the way it spins.The polarizing properties of this filter are quite good. A polarizing filter's effectiveness is dependent on one’s angle of perspective in relationship to the reflections, or light source. One can dial out harsh reflections from floors, windows, water, anything reflective (but not chrome) providing they are at a 90-degree angle to the light source causing such reflections.Because a polarizer will add more contrast to your scene, it is a great way to add snap to your photos, especially to boring skies (see example image taken with this filter using a 28mm lens.) Be careful when shooting a sky with a lens wider than the equivalent to a 28mm or 24mm lens. The polarization may make the sky's tonal value uneven. No need to worry about vignetting, as the filter is super slim.Another benefit in using a polarizing filter is to use them for a tiny bit of neutral density. This will help select a slower shutter speed.Since a filter is mounted close to the front or back of a lens, any imperfections are so out of focus, they can't be noticed. Also, as long as a filter is made of optical glass, generally speaking, any loss of sharpness shouldn’t be an issue.After 32 years of being a professional photographer, Id like to share my thoughts on when to spend more on a filter, and when to spend less.-Spend less if you need to protect many lenses with an UV filter. Your savings will be quite a bit and the quality isn't such a step down. If you need to shoot for an assignment, or if you are about to make a great capture, you can always remove the UV filter and then later put it back on.-Spend less if you aren't sure how often you may use the filter.-Spend less if you are starting out.-Spend more if you need water resistance.-Spend more if you sell your work, or use step up rings, and only need a limited amount of filters.-Spend more if color accuracy is the most important aspect.

I bought these for use on my Canon IS binoculars and they are perfect. The attached/leashed lens caps are perfect for my use on the water on boats. The conditions are usually bright and the filters cut the glare exactly as they are designed.

Judging this glass by professional standards is just unfair, so I've decided to revise my 1-star rating.Here's why I initially gave it 1 star: the polarization effect is rather weak, and it gives polarized light a yellow/blue tint. So if you're a working pro who relies on polarized filters... well, you won't be looking at $20 polarizers, hopefully.However, for the vast majority of amateurs, videographers and casual users this filter will more than suffice. Tint shifts won't matter if you color grade your video footage or apply any "looks" to the photos. The weakness of polarization is actually beneficial for beginners, as it will save them from the typical wide angle sky shots (if you know, you know). As an added bonus, this filter is much brighter than most pro grade polarizers (with the exception of high transmittance ones that tend to cost 10x as much).In other words...Who is this filter for: vacationers, amateurs, videographers.Who should look elsewhere: anyone who requires a strong polarization effect and/or scientifically correct colors regardless of polarization. But then again, even Zeiss has a rather noticeable blue shift in polarized light... B+W Master series are quite neutral through and through, but cost 10-15x more than K&F. At the end of the day, you get what you paid for.PS: I absolutely love round cases that K&F filters are shipped with, they are magnitudes better than generic boxes that come with Tiffen, Hoya or B+W filters.

Lenses cap does not engage well.

I think it works well but it’s almost impossible to get off and now worries about messing up my lens. Probably wouldn’t buy again.Update: changed to 5 stars because of the excellent customer service. They reached out and dealt with my issue immediately.