tested quickly with one photo and the effect is ok, but not as strong as I was expecting.
The case is way too big, so not very pracical for 49mm.
3 microfiber cloths are included... but to be honest I would rather have a better case and maybe a reduced price instead

Decent coating for the price of the filter. It does its job and for a great price.

The price was well worth it, I don't see the point in spending double the money on something that produces a great image as good as this

La calidad y nitidez de la imagen no se pierde con este filtro a diferencia de otros filtros mist baratos. La difusión de las luces es muy suave, perfecta para darle el look que se busca

I absolutely love this filter! I was looking for something to soften up my pictures without breaking the bank and I came across this filter (43mm) for around 17 dollars after tax. It is super small and discrete to the point that I forget that it is on my lens half of the time.

I decided to get the 1/8 black diffusion filter rather than the 1/4, 1/2 or the 1/1 because I was looking for just a subtle glow and this thing definitely delivers. For me it is perfect, but for others the 1/8 may be TOO subtle in regular conditions. I will say however that the bloom effect really shows through when a scene has a lot of direct light or very bright highlights. I also chose the 1/8 version because I wanted a slight artistic flare to my photos without feeling too intentional with the bloom. I will also mention that I don't have the ability to determine the filter's sharpness and while I suspect that it maybe lowers the sharpness of the overall picture by a tiny minuscule bit, for many of the pictures that I took I was more than happy with the quality that it produced. If you are concerned about the sharpness I would probably look into the Tiffen filters, but even with that, those filters are 6x the price of this one.

If you are a starting out experimenting with filters and do not want to spend too much money, this is the one. There is so much fun and artistic capability that can be achieved with this filter that I keep it on my 23mm all of the time. Buy this filter!

I included two pictures of a cyclops action figure and you can really see the effect on the flash light at the bottom left of the picture as well as the overall bloom on the figure itself. I also included a few other shots with very bright highlights.

I didn't notice any color. Changing, it was an amazing price and it stays on whatever stop you leave it on. No X pattern and I didn't see any quality loss.

Love these filters! Great brand!

Nice diffusion/halation effect on and around highlights, doesn’t break the bank when searching for a diffusion filter like tiffen does. Excellent build quality. Definitely recommend this filter

So, I recently tried out this K&F Concept Diffusion Filter, and I’ve got to say, I’m pretty impressed. It gives my photos this subtle, dreamy effect without going overboard. The thing I really appreciate? How easy it is to slap on and then take off when I’m done. Plus, it feels solidly built, not like it’s going to fall apart on me anytime soon. If you’re looking for that slight glow in your shots and want something that feels reliable, this is a solid pick.

It works very actively, it might be nice to have a set to adjust the effect.