Very subtle through the viewfinder, but there is a noticeable affect on exposure time. For achieving a vintage portrait look, this thing is fantastic, especially when coupled with a manual focus legacy lens - I have mine on a Rikenon 50mm. Sharpness is greatly reduces, but not in a "cheap lens" way, just a subtle and even softening. This brings to mind the famous Pentax "soft focus" portrait lenses of the 70s, but is a far less blurred image. Handy to have in the kit bag, but not really good for much other than portraiture. I have yet to try a K&F product that I am not absolutely impressed by.

So I think a lot of folks involved in video product are very familiar with the Tiffen Black Pro Mist filters. This is K&F's version of that filter. I will go into what I think about the filter but you can also judge for yourself in one of the pictures in this review where I show you the same image; the first without the filter then with the filter.

One of the results you get with a filter of this type is blooming of the highlights. This filter does quite a good job of that. Comparing the bloom to the Tiffen line I would say it falls between Tiffen's 1/2 and 1/4 strength with it being closer to the 1/4. The highlight fall of was strong but natural in my opinion. Keep in mind the light in the image fills the frame so you are seeing this particular effect of this filter at it's most extreme. You won't see that much blooming in a more natural setting. Take a look at the highlights on the camera. To me the K&F filter had a great effect on the highlight roll off which was very smooth.

The other effect you get with a black mist filter is the slightly reduced contrast and the slight softening of the shadows. To me I thought this filter did this quite well. If you look at the texture on the handle of the camera in the image you can see how it's just sort of softened that texture. Imagine shooting a person and you can imagine how much you would be able to smooth out the skin.

It also comes in a nice little screw together plastic case. Inside the case are these little rubber stopper than prevent the filter from sliding around in the case. I love the attention to detail here.

So compared to the Tiffen version of this lens at the size I got which was 82mm the K&F Black Mist is about $40 cheaper. I think you are getting a lot of value for your money here. I can't wait to try out this filter on some upcoming shoots.

I think K&F is making a move into higher end filters and if this filter is an example of the kind of quality they can produce, I can't wait to see what filter they release next.

Would 100% recommend

I always get filters w/ non-slip design when it's available. It makes a huge difference. I compared it w/ Hoya HD2. I shot these w/ Canon M50 w/ Nikon 35-70mm f/2.8 AF ZOOM-NIKKOR.
1) No filter. 2) K&F. 3) Hoya HD2.
Sure, it's not a great test but I can't tell any difference between all 3 of them. The Hoya was optically as good as K&F except it was very staticky that I had to return it. I didn't like it's not non-slip either. The K&F is not staticky at all and very easy to clean. When there's no reflection, it looks like there's no glass inside the ring. Kind of like magic. It's very well made.
I use it on my Zeiss 50mm f/1.5 Sonnar T* ZM. There's no play and it fits perfectly. Very happy about the purchase.

Just got a new lens, needed a 77mm filter to protect it. I'm not going to sit and tell you this glass is better than some other glass. I just got it, and I'm not an optics expert.
But, I will tell you the packaging was beautiful, the filter case- one of the nicest I've ever seen. It is circular- and holds multiple size filters with grooves in an internal bracket. So much nicer than the big clunky square filter boxes I've got from other brands.
But- the killer was the filter being so thin- and that it has 2 areas that are gnarled, for you to grab it- while the rest is smooth- a really nice feature.
Seems right at home on my Canon RF24-105/4 L IS USM.
Didn't notice any difference in speed of focus- or aberration- but, again- I'm not a lab.
I'm pretty happy with this brand. Didn't expect to be

I purchased this for a camera that I seldom use. It still is a valuable collectors item that I want to keep in excellent condition and that means I needed to protect the lens. I only have filters with the Zeiss "T" coating constructed of German Schott glass on the cameras I use frequently, because I consider them the best multicoated filters that I can afford but, I cannot spend that kind of money for a camera I use infrequently.
Any camera that is threaded to accept a filter deserves the protection that comes with a mounted filter in front of the actual camera lens. I would rather risk damage to the AR coating on a filter that can be easily replaced than risk damaging the actual lens on any of my cameras from cleaning, and exposure to airborne dust or chemicals.
This brand of filter came carefully packed and the filter holder included with the filter is well designed and provides excellent protection for the filter when it is not on the camera lens because I am using a different type of filter. This filter has multiple AR coatings on both sides of the filter and after comparing the results of identical pictures with the same camera using this filter and one of my prized and now unaffordable Zeiss "T" filters I can say that I can see no difference in the results. I am sure an optical lab could document some differences, but in the real world, I can see no differences when comparing the test pictures I captured through this filter and the Zeiss filters I have used.
This design works so well, I will slowly replace the older non Zeiss filters I have on my older lenses and cameras with these newer designs.

GREAT PRODUCT. COMES WITH A NICE CASE ALSO.

Very suitable for taking pictures of silky water. Good quality glass and threads are essential for any serious photographer.

Nice filter. Definitely comes in handy in certain situations. Great for sharp lenses, especially those with no character. That brings some mood. It's nice to have, looks good, and I love that I can apply it to a lens and still use the lens cover over the filter when it's not in use.

I am usually against UV/haze filters as I am concerned about their effect on image quality. However, I plan to use my Sigma 150-600 DG DN Sport (Sony E-Mount) in pretty harsh conditions such as coastal bird photography, surf photography, and sports. So, I caved and purchased this filter to provide protection for the lens front element.
However, given that this K&F filter would probably be considered "mid-tier" in terms of price, I wanted to test if it in fact had any effect on image quality. The attached image of a $20 dollar bill was taken under the same exact circumstances - 600mm at ISO 100, tripod with OS off. As you can see from the screenshot taken in the compare view of my photo editing software, the image on the right (with filter) is clearly sharper with better contrast.
I'm shocked! I had fully expected to remove the filter when I wanted a better image. Now I can leave it on 100% of the time, and easily wipe off any splashes or dust without worrying about scratching the front element. Strong recommend!