Review on SIOTI Square Filter Kit 100X150mm (4X6'') with ND2, ND4, ND8, and ND16 for Cokin Z, Lee, Hitech, Sioti Holder (ND) by Michael Freemason

I used these square filters instead of round ones to capture waterfalls with slower shutter speeds. I also bought a set of square SIOTI filters to keep. I'm not a professional landscape photographer, so I didn't want to spend a lot of money. The filters aren't exact in density and color, but they work as you'd expect for the price. This is a good value for those who don't want to spend $70-$100 on a professional filter. The ND16 didn't live up to expectations and I'll talk more about that later. The filters look like plastic and should last with good care. They are individually wrapped in a plastic bag in a soft plastic sleeve. Each sleeve is marked with an ND# number. This can serve as a place to store filters if you don't mind fiddling with flimsy plastic in the woods. If that doesn't sound like fun, you should look around for a filter housing. I tested each filter with my D750 and a 24-120mm ƒ4 lens set at 50mm. It's not laboratory accuracy, but I wanted to get an idea of what to expect. I placed the calibration card about 2 feet away on a white background and placed a continuous light source about 1.5 feet from the card. The camera was mounted on a tripod and set as follows: white balance at 6400, ƒ5.6, ISO 100, 50mm and started at 1/50s. I switched each filter and photographed until I got the same exposure based on the histogram. Each filter blocked more light than expected, had some blue cast and, with the exception of ND16, sharpness didn't suffer much. See photo for comparison. Each panel is a 100% crop of 5 frames at the closest exposure. - Result: 3 2/3 stops, ND16 pale blue (4 stops normally) - Result: 9 1/3 stops, deep blue, slight loss of clarity This requires additional color correction and sharpening in the software, not to mention that it is not the one expected light reduction is. The wrong filter may have been packed. I haven't tried the filters in the real world yet, so I'm not sure it's worth returning without the 4-stop filter. When I wanted to add filters to get 6 to 7 stops I had no luck. (People say you shouldn't use more than 2 filters at a time to get the best sharpness.) $30 for 4 filters seems reasonable so far. I'll definitely update if my expectations aren't met once I get to the place. Thank you for reading. I hope this helps you with your purchase.