These filters are well built and pretty good quality, and they even include a nice carry case. Where they save on cost are on the glass and coatings, but you can do a lot with this set. You may not notice artifacts unless you adjust to very strong to maximum darkness settings on the ND filter. If you do that kind of work, you may have to spend a couple hundred for some very pro filters and even they have their limits too. But if you do some post edit work on your images to get the right colors you like, and retouch images anyway, you get a lot for your money here.

This is a great set of lens filters, and at the price they are it feels like a steal! I like how it comes with a carrying case and microfiber cloth. I got the 37mm set for my Camp Snap Pro. I've tested them all out and they definitely work well, the UV filter absolutely helps to bring out vibrant colors on outdoor pictures and keeps them from looking washed out. The ND filter works very well and has adjustable stops, on the first stop it's barely noticeable, the last stop on it made my living room look like night aside from the window which shifted from a glare to being able to see everything outside clearly. Polarized filter seems to work as well, but I haven't been out to a large body of water to give it a thorough test. All in all it's a great set of lenses for anyone that wants to get more experimental with their photography hobby.

I am delighted with it a good quality

I use this K&F Concept 67 mm kit as a simple all‑round set on my walkaround zoom and it has been a convenient way to get UV, CPL and variable ND in one pouch. The variable ND2–400 gives roughly 1–9 stops of light reduction, which has been enough to keep shutter speeds slow for motion blur in waterfalls or traffic and to shoot wide open at f1.8–f2 in bright midday light without blowing highlights. The Nano‑K coating keeps colour fairly neutral and helps cut flare and reflections, so I have not seen strong colour casts in normal use, though at the very darkest end any variable ND can start to show cross‑pattern artefacts on ultra‑wide lenses.

The CPL is handy for cutting glare on water, glass and foliage and to deepen skies, and the separate ring lets me dial in polarization independently from the ND strength, which is useful for video. The UV lives on the lens as a general protector; it is slim enough that vignetting is minor on most 67 mm zooms and the multi‑coating makes it easy to wipe clean. Build quality on my copy has felt solid for the price, with smooth rotation and an aluminium frame that has not bound or jammed in the filter threads. For casual landscape and travel work this kit has covered almost everything I need without having to carry multiple branded filters.

The K&F Concept Nano-Klear 58mm Kit is a highly recommended option for amateur and enthusiast photographers. While it doesn't have the clinical color neutrality of premium brands, it offers 90-95% performance for a fraction of the price of other brands. The quality of the glass is crisp and the Nano coating is a quality feature you'll appreciate every time you have to clean the lens in the field.

Includes: UV (Ultraviolet)
filter: Primarily for protection.
CPL (Circular Polarizer) Filter: To eliminate reflections and saturate colors.
ND4 (Neutral Density) filter: To reduce light (8 steps) and allow longer exposures.
Carry case: A padded wallet-style bag.

If you're just starting out, it's a good option for your goals.

For those that don't know, K&F makes some exceptional glass filters, but they also have K&F Concept that produces some more budget-friendly products, which is sorta the equivalence of Donna Karan running less expensive products out under the name DKNY. The K&F Concept filters are perfectly good, but tend to be made with compromises, and sometimes it takes a little knowledge or understanding to use them well.

So there are three filters in this set, but what I said above is mostly relevant to just the variable neutral density (VND) filter. If you buy higher end VNDs, you tend to get two of them, with one covering a low range of stops and the other starting fairly dark and only going much darker. The reason for this split is because the polarization effect that's used to create VNDs is unavoidably going to cause some weird optical effects if pushed too far. Specifically, it creates the dreaded "X" effect where there's just an uneven exposure in the shape of a cross.

So why did K&F Concept opt to sell an ND filter that gets the X effect? Well, it costs less to make one filter than it does to make two, so they're opting to make that compromise so they can sell this pack of filters for less.

All it takes to use this ND filter well is to not push it too far to the darkest end. That will limit the kind of shots you can take without it effecting the image, like you aren't going to do any super long exposure shots. However, this ND filter will be perfectly good for things where the lower and middle range are more useful, like shooting video, capturing some streaky waterfalls, and maybe even some short light painting.

In my tests with the filters, none of them produced any appreciable color cast, and I didn't see any sign of distortion or blurring. If we're getting really picky, there was maybe a bit more loss of contrast than I expected from both the ND and the CPL, but that's not weird, and it can be adjusted very easily in post.

The CPL and ND generally do their jobs well, so outside of pushing the ND to the max, I don't think there's anything wrong with these. Now I will briefly comment on the UV filter, because these are utterly pointless for anything other than putting a piece of glass in front of your lens. If you want it to be physical protection, go ahead. Otherwise, don't believe any story about UV having any effect on modern sensors.

While I'll generally argue these filters are good and well worth their price, I will criticize the case that comes with them. The outside of the case is great. It's nothing fancy, but it barely flexes and it zips / unzips fairly well. The problem is the dividers inside, which are made with nylon that feels almost abrasive. And if any sand or grime gets into the case, this material will virtually ensure these filters get scratched.

Love the filters on my Sigma 30mm f1.4! Great quality! Fits perfect! The value was awesome! Protects my lens from glare too!

This is a well packaged set of quality filters at a good price.

Can't go wrong with K&F filters. Sharp and solidly built.

Great all around kit, and love the holder