SIOTISquare Filter Kit 4X6'' (100X150mm) with ND2 & ND4 & ND8 & ND16 for Cokin Z Lee Hitech Sioti Holder (ND)

Excellent filters for the price, look well made and have held up well!

Well packaged, great value for money for the amateur photographer.

I got these square filters to use instead of round ones to take longer exposures of waterfalls. I also purchased the SIOTI square filter kit to hold them. I'm not a professional landscape photographer so I didn't want to drop a lot of coin.The filters are not precise in density and color, but perform as one might expect for the price. They're a good value for anyone not wanting to drop $70-$100 per pro filter. The ND16 did not meet expectations, and I'll go deeper on that later.The filters look to be of a plastic material and should hold up if taken care of. They are individually packaged in a plastic bag, inside of a mildly padded plastic sleeve. Each sleeve is labeled with the ND#. This could serve to store the filters if you don't mind messing with thin plastic out in the woods. If this doesn't sound fun, you'll want to look for a filter pouch.I tested each filter with my D750 and 24-120mm ƒ4 set at 50mm. It's not lab precise, but I wanted to get an idea what to expect. I placed a calibration card about 2' away on a white backdrop and placed a continuous light source about 1.5 feet from the card. Camera was placed on a tripod and set as follows: white balance to 6400, ƒ5.6, ISO 100, 50mm, and started at 1/50s. I swapped out each filter and shot till I got the same exposure based on the histogram. Each filter blocked more light than expected, had some blue color cast, and except for the ND16, sharpness wasn't effected much. See the photo for a comparison. Each panel is a 100% crop of the 5 images with the closest exposure.ND2 (typical 1 stop) - Result: 1 1/3 stopND4 (typical 2 stop) - Result: 2 1/3 stop, slight blue colorND8 (typical 3 stop) - Result: 3 2/3 stop, mild blue colorND16 (typical 4 stop) - Result: 9 1/3 stop, dramatic blue color, slight loss in clarityAll results are satisfactory to me (considering the cost) except for the ND16. That'll require more color and sharpness correction in software, not to mention it's not the expected light reduction. It's possible that the wrong filter was packaged. I haven't tried the filters in the real world yet, so I'm undecided if not having a 4 stop filter will be worth returning them. If I wanted to stack filters to get 6 to 7 stops, I'm out of luck. (People say to not use more than 2 filters at once for best sharpness.)$30 for 4 filters seems ok so far. I'll be sure to update if my expectations are not met once I get to a location.Thanks for reading. I hope it helps you with your purchase.

Great cost affective filters. If you are on a budget these are the ones to get. Others can be very expensive.

The optical quality on these are completely unusable. I just did a series of test shots and could NOT get a tack sharp picture with these filters at all.I'm using a Canon 6D Mark II body with a 70-200mm F2.8L IS Mark I lens. I've attached comparison images for with and without the filters with the camera set in aperture priority fully open at 2.8 and ISO set to 400. These are handheld, but with the SIOTI filtered image at 1/250sec handholding should not be an issue with blur.These images are SOOC RAW images. I'm standing 10-15 ft from a test subject that had a lot of contrast.I can't use these filters at all. Also note these are using the SIOTI 100mm Square Z series Aluminum Modular Filter Holder, which appears to be decent quality. My issue is with the optical quality of the filters themselves.