[Glass] I have used this filter for my work for two years and it is perfect. I can use it in my Cokin Z-holder but more often than not just hand hold it. It can easily be combined with a CPL or other ND filter to achieve 4-extra stops which help with waterfalls on sunny days, softening clouds, getting a soft ethereal texture from crashing waves and streams. The nice thing about it is that unlike using very high density screw on ND filters which might make it very difficult to see and focus, especially when using slow f/5.6 lens, you can compose, focus, then use the AF button to lock focus, hold the filter over the lens or other filter, then exposure and click. Very simple and effective. I use this filter a lot. I used to own the extremely expensive SR vari-ND but I sold it for this one because 1) it vignettes at wide angles, 2) does not meter properly due to the physics of the design so you must take test shots and use an iterative approach 3) you can easily over dial in the density which results in a 'cross' in the center where the two polarizers meet. You can't see this effect in the viewfinder since it would be too dark but the result is obvious in the LCD screen. Bottom line, it is much faster to use this filter than a vari-ND and since a vari-ND vignettes at ultra wide angles you end up needing two sets of filters which is just a waste of money. I use this filter a lot along with about 10 other filters which I keep in my two filter pouches that include grad-NDs, CPL, and yes, a screw-on 3-stop ND. No color cast, fast and easy to use compared with any alternative, and very affordable.

[Glass] Fits perfectly in the Cokin P holder and great for landscape photography.

[Glass] These Hitech filters are very nice, although made of plastic they don't seem to affect image quality at all. I'm not experiencing any magenta hues or anything odd.

[0.285 lb] Used for very long exposures in landscapes, I appreciate this extremely well made piece of kit. It does not let me down in any way.

[Glass] make sure you look into the lvl of ND you want in advance

[0.285 lb] After 5 shots I dropped the filter from about 5' onto asphalt. The ring was a bit scratched but the glass was fine and screw worked as well. Thankfully its a well made filter. I also got some pretty interesting shots with it.

[Glass] I always wondered how to get that creamy effect in a waterfall picture, and this was the answer. Coupled with a good tripod, I can now get some excellent waterfall pictures.

[0.285 lb] I use this for cutting light for long exposures. Primarily I use it for photographing lightning where a long exposure is required even in light conditions. This one has a filter factor of 8 stops, it works great. A neutral density is a staple in my gear bag.

[0.285 lb] In my testing of the HiTech filters I shot the images in RAW format with some of my best gear. I attempted to color correct the images with a Passport ColorChecker. I had little luck with the 10 Stop (ProStop), some modest success with 7 stop (ProStop)filter, but did get a very workable image with the 4 stop filter (Standard).The base camera settings were:WB set to ShadeAv set to f/8ISO set to 100My processing included the following steps:1) Eye dropper white balance correction on the neutral square2) Export the image to ColorCheckerr Passport to create a custom camera profile for the image3) Restart LR4 and apply the custom camera profile4) Apply the LR4 preset for Scenic Sharpen5) Export to JPG filesThe 10 Stop:Temp shift from 7,000 to 50,000 (maxed out)Tint shift from +7 to + 114The 7 stop:Temp shift from 7,000 to 13,750Tint shift from +7 t0+81The 4 stop:Temp shift from 7,000 to 8,300Tint shift from +7 to -1The NON-Filtered:Temp Shift from 7,000 to 7,900Tint shift from +7 to +12

[Solid ND] cheap but nice, strong build, fits all lenses