Fotodiox Graduated ND (Neutral Density) Filter

The gradual fade from dark to clear is perfectly smooth, so I get natural-looking skies without a harsh line. Stacking it with my polarizer was easy thanks to the double threading.

The double-threaded ring is a nice touch—lets me stack my polarizer on top without any vignetting. The transition from dark to clear is smooth, so my skies look natural instead of having a harsh cut-off line.

I shoot a lot of landscapes with bright skies, and the gradual fade on this filter is so smooth you never see a harsh line. It stacked perfectly with my circular polarizer thanks to the double threading, which saved me from buying a separate adapter.