Pro-Mist Filters

[kye]

13 minutes ago, bjohn said:

No, it's due to the filter. See this comment from Ryan Avery, who knows a thing or two about lenses and filters:

http://disq.us/p/28697ul

"As with all filters like the Tokina Black Alchemy, Schneider Hollywood Black Magic, and Tiffen Black Soft F/X; you have avoid long lens bokeh effects (in focus subject in the foreground with out of focus lights in the background such as cityscapes, streetlights, panel lights, etc), and avoid shooting wide open past T2 on sensors S35 and above. The filters hold up perfectly as long as very apparent point source bokeh where the subject is close to the lens are avoided. Once at deeper focus, further from the lens, the effect speckle bokeh is gone."

We're agreeing.

The article you linked says that "Clear Supermist is made of fine clear colorless particulate that is bonded between two pieces of Schott B270 Optical Glass which exceeds 4K resolution capability." and "Black Supermist is made of fine black color particulate that is bonded between two pieces of Schott B270 Optical Glass which exceeds 4K resolution capability."

Particulate refers to something being a bunch of particles.  ie, it's tiny lumps of stuff - it's not a continuous smooth layer of something.

The optical effect appears to be that when you have a bunch of stuff (lumps, bumps, patterns, whatever) very near or inside the lens, then that texture somehow becomes an in-focus mask on out-of-focus areas.  This is why the texture of the meshes that I linked in the article I shared also showed up, and these were attached between the camera and the lens.

You can also use this effect for special effects:

Once again, this is the shape of something close to or inside the lens creating an in-focus mask on the out-fo-focus areas.

Tiffen are just using a mask made of tiny particles that have optical diffraction effects rather than just casting a silhouette, although it's the same optical principle that makes the texture appear in-focus.