Does anyone have information on the Mitchell variable diffusion filter and any ideas to make a modern implementation?

[Edith blazek]

Basically what the title says. It's described as unit that "utilizes two gradated Mitchell diffusion filters to increase the strength of the effect as they are slid against each other via a geared track." Now what I'm interested in is how one could go about making a modern day version of this, I imagine to work with modern day matte boxes the filters would have to be super thin but how thin and how to get the effect I don't know.

[Charlie Peich]

Mitchell Variable Diffusion Filter Holder....

 

 

Good luck!

Charlie

[Edith blazek]

37 minutes ago, Edith blazek said:

Basically what the title says. It's described as unit that "utilizes two gradated Mitchell diffusion filters to increase the strength of the effect as they are slid against each other via a geared track." Now what I'm interested in is how one could go about making a modern day version of this, I imagine to work with modern day matte boxes the filters would have to be super thin but how thin and how to get the effect I don't know.

Now I have leaves me with two conundrums, 1, how would I go about making a filter tray that would support the movement and length of the filter? And 2, who would be willing to make a filter to the required specification? That I don't know, maybe this is pointless and stacking 2 filters will do just fine, but the allure tho....

Edited October 31, 2023 by Edith blazek
Too late before someone replied

[Frank Wylie]

Search for a seller named "Kinemaman" on Ebay and inquire if they have any leads on an original Mitchell unit.

From what I know, they have one of the largest stockpiles of original Mitchell camera gear in the World.

[David Mullen ASC]

Here’s a sliding Mitchell that Roy Wagner, ASC owns.

[David Mullen ASC]

You could use two 6x6 filters and slide them in from opposite directions (or just slide one but the effect would appear to roll in from one side) but they would have to be graduated diffusion filters… the only ones I ever recall being made were the old Scenic Fogs from Harrison & Harrison.

[Mark Dunn]

6 hours ago, Edith blazek said:

stacking 2 filters will do just fine,

If all you need is a range of diffusion for various shots, that's probably right. As the manual says, the idea behind this gizmo is to be able to vary diffusion during a dolly in from long shot to CU, or vice versa.

I'm not sure I've ever seen it done- or noticed it, anyway. Which probably means it worked.

Edited October 31, 2023 by Mark Dunn

[David Mullen ASC]

Truth is today if you had to go from a wide shot to a close-up needing more softening, you'd probably do it in post, or half in post, use a very light filter for the start and then soften the face in color-correction as you pushed in.

Unless this is more of an effect of a dream sequence beginning where you want a misty look to roll in.

Mitchells weren't the greatest diffusion, they tended to blur focus too much. They used a pattern of etched diamonds in a chain link fence design, sort of like the glass equivalent of a net weave. But they didn't allow enough flat areas of clear glass spots to allow sharp lines to pass through -- true diffusion is the overlay of a blurred image on a sharp image.

You can see the etched chan link pattern of a Mitchell here in the bokeh, from "Psycho". A net diffusion would have a similar pattern but dark lines not white.

[Jeff Bernstein]

Compare the sharp clarity of the telephoto bokeh in the above image (1:03:29 uncut) with the hazy telephoto bokeh at (1:11:30). In the first, the hard clarity helps to convey the keen, sharp intelligence of Lila Crane. In the second, the haziness helps to convey the lazy obtuseness of Arbogast. Also, in the second, the hazy bokeh helps to convey the uncanny mystery of the dark void encompassing Reason—the antithesis to everything the Hardware Store suggests : the brightness of “everyday common sense”. Soon, however, the darkness of (1:11:30) invades even the Hardware Store (1:19:53) . . . just as Lila and Sam begin moving toward a Revelation that will undercut all certainty—forevermore.