What filter would bring Sigma FF High Speed Primes close to Nikkor Ai-s lenses

[Markus A Ljungberg]

I'm prepping for the final leg of a project that has previously been shot on Nikkor Ai-s lenses, and the odd Zeiss ZF. 

I'm going to shoot with the Sigma FF High Speed Primes instead, and I wonder what filter could bring them closer to the Nikkor Ai-s look. I think they need lower contrast, a bit of halation, and possibly a bit of softening. This leads me to think maybe I should use a Black Pro Mist filter. Maybe 1/4 strength? Any suggestions from the forum? I'm also considering Glimmer Glass and Hollywood Black Magic. 

Ideally, I would do a test of course but there is little time available and I'm not being paid for prep. 

Reasons for swapping lenses are 1: They had issues with previous footage being too soft (Director likes to zoom in digitally in post) 2: My own camera is PL mount and I own a set of Sigma FF High Speeds (There's no budget to hire anything externally) 3: Improved speed on set with standard front diameter and same distance to focus gears across the line. I'd like to avoid the hassle of shooting with still lenses. 

Thanks in advance for input, cheers

[David Mullen ASC]

Generally the difference between many lenses is not as strong as the lightest diffusion filter but certainly a #1/8 something would help, not a #1/4 Black ProMist, which definitely adds a ProMist look.

I think these days the #1/8 Black GlimmerGlass (Tiffen) or the #1/8 Black Frost (Schneider) are probably the lightest mist filters. There is also now a Tiffen #1/8 Black Fog that you might check-out.

I wouldn't go any heavier; you can finish matching the lenses in post color-correction (truth is that you don't even need filters to match them, you could do it in color-correction as long as you are "dumbing down" the sharper image to match the softer one.)

[Markus A Ljungberg]

Thanks David. The Black Fog is new to me, that sounds interesting, I'll look into that.

1/8 sounds like a good shout. I think it's mainly the halation I would like to get in camera, in my experience it's a bit time consuming getting the halation right in post. Following that logic, BPM makes less sense, your suggestions sounds better. Thanks 🙂  

[David Mullen ASC]

Schneider's Black Frost is sort of a newer version of Tiffen's Black ProMist and I think it's slightly better especially as they get heavier in strength like the #1/2 -- but on the other hand, the Tiffen Black GlimmerGlass is even better than either if you want to retain some sharpness, especially in the #1/8 to #1/2 range, which are pretty subtle.