I haven't had the change to do real world testing yet but I've taken a few test shots in my garden to check for loss of sharpness and color casting. I used a macro lens for checking fine detail and wide angle to see if its consistent across the frame. I also checked it against my Lee Filters big stopper.I couldn't find any percievable loss of sharpness across the entire frame with the macro or wide angle.There is a bit of a color cast to it from looking at the exif data but shooting in raw the camera adjusted it out for the most part and can be edited out manually if required. Importantly though it seems to be consistent across the entire frame, even at 10mm on my apsc sensor.I did experience vinetting on the wide angle (both 10mm and 22mm) but again it can be edited out very quickly in lightroom.It would have been nice if it came with a light gasket supplied with it but for the massive price difference compared to the bigger brands I can forgive them for that. They can be purchased online elsewhere if required which is what I'll be doing.Overall I'm pretty happy with it, which is just as well really as it managed the slip through my Lee Filters folder when I wasn't paying attention and drop onto the paving slabs in my garden, which chipped the corners of the glass. That's my own fault though as it's a known issue I have with the holder, I experience the same problem with my Nisi filters in my holder so I think it's a bit worn out.

I currently have a 12 stop ND filter that I find can be a little heavy handed at times and wanted a 6 stop ND.
After seeing the promotion ads I thought I’d give this K&F Concept filter a try. The sale price was too good to pass up, my order arrived a few days faster than excepted which is always great. The filter was well packaged, love the pouch with pull tab which makes getting the filter out much easier, the filter quality looks to be great, equally or better then my current filters, hopefully I can test this 6 stop ND within the next few days!

K&F filters are value for money. Deliver the quality a photographer expects.

I currently have a 12 stop ND filter that I find can be a little heavy handed at times and wanted a 6 stop ND.After seeing the promotion ads I thought I’d give this K&F Concept filter a try. The sale price was too good to pass up, my order arrived a few days faster than excepted which is always great. The filter was well packaged, love the pouch with pull tab which makes getting the filter out much easier, the filter quality looks to be great, equally or better then my current filters, hopefully I can test this 6 stop ND within the next few days!

Nothing to dislike

I have two K&F lightweight tripods. They are excellent and I use them regularly. I recently purchased a 100mm 10 stop ND filter for long exposure photography. Before I was able to take my first picture with it, the filter slid straight through my Lee 100mm filter holder onto the ground and smashed into a myriad of pieces.So I contacted K&F and they have replaced it for me. Very good service

This is high quality ND filter. And it's package like Giorgio Armani products ;-)

These are not cheap but comapred to Lee Filters a bargain. The filter holder is excellent, and is supplied with multiple adapter rings, which are £26 each from Lee. I can see no significant colour cast. So if you want to experiment with proper filters without breaking the bank these are a good buy. The filter cases are beautiful and the whole product presentation/packaging oozes quality.

Tried the filter a few times with landscape shots. Worked really well. Not affecting image quality or producing colour cast. Very happy with the product and purchase.

Excellent with little colour shift which isn't really relevant with post processing. Found it a fraction out in real world testing in stops and no great loss in sharpness but I'm just nick picking. Do your own tests to find the perfect settings. At the price it's good enough for most photographers.