Promaster 100 x 100mm IRND8X (0.9) HGX Prime 3 stops

The 2mm thickness fits my holder perfectly with zero vignetting, and the 3-stop reduction gave me exactly the silky water effect I wanted on this overcast morning. Color cast is almost nonexistent, so post-processing was a breeze.

I've been using this filter for landscape shots and the 2mm thickness is a huge plus—it slides into my holder without any vignetting on my wide lens. The IR coating cuts the color cast I used to get with cheaper ND filters.

Finally got this square filter for long exposure seascapes, and the 2mm thickness slides into my holder without any light leaks. The 3-stop reduction lets me get that silky water effect even in bright midday sun. Colours look perfectly neutral, no weird colour cast to fix in post.