K & F filters look to be good value and well respected in the industry.
I decided to add a 62mm (my “big” size) 2-400 variable ND and 46mm (most of my primes) 1/8 Black Mist.
The BM 1/8 is going to be close to, but slightly different from the Kenko 05 and lets me have two cameras filtered up at once. I like these in comparison to the Tiffen Balck Mist, looking slightly less aggressive. One reviewer, a rare Kenko vs K & F reviewer, stated the K & F is “grittier” or less clean looking than the Kenko.
The Var ND is the same and will let me be more versatile with my “run-n-gun” Olymus kit. The fixed ones have more optical stability so give me more confidence, but some times a variable is handy, even if they have issues with some light sources. I went the Nano-X VND, the one with the green reflective finish and orange lever.
The Kenko is smooth, maybe slightly too smooth for all situations, the K & F is more aggressive and the two could be used together to make a 1/4.
On the shopping list, are the Kase Blue Anamorphic Streak and Tiffen Glimmerglass, both likely bought from the U.S. as any other source is way dearer for these.
The Anamorphic look also really appeals, although I do wonder if a Kenko 4 or 6 point star would be a cheaper and (for me), as effective option. The basic idea with either is light streak, being linear (anamorphic) or multi (star).
The Glimmerglass, as well as the Tiffen Satin, are two of the few Black Mist style filters that do not lighten blacks too much, just reduce sharpness, which i like. This is the true Black Net look of the pre digital period.
More research needed.