Tiffen Magnetic Rear Filters for ARRI Signature Prime Lenses are now approved, tested and authorized by ARRI. They come in many of the popular Tiffen looks and grades: Glimmerglass, Promist, Fog, Black Satin, etc.
Why is this so good?
When mounted on the rear, you can use one strength, for example ¼, on the entire range of focal lengths. You do not have to change strengths depending on how wide or tight you are.
This is different from when you add a filter to the front of the lens. Hopefully you use a heavier grade for wide angles (maybe ½ or 1) and a lighter grade for tighter angles (maybe ⅛ or ¼).
The reason for the uniform grade is telecentric design. On the Signature Primes, the rays that emerge from the rear of the lens are parallel, no matter whether you are wide, medium or tight. Also, none of the Signature Primes have rear elements that protrude through the rear of the LPL mount.
There are 12 magnets at the rear of ARRI Signature Prime Lenses. You probably already have ARRI net holders that attach the same way. Now, you can swap rear magnetic filters quickly; no need to screw on and unscrew.
Have we seen this before?
ARRI recently introduced eight Impression V filters—essentially plus and minus diopters for the rear. Now, with Tiffen Rear Filters, the choices to define new looks are increased.
Tiffen also makes rear filters for Angénieux Optimo Primes.
But why have we mostly used gels and nets in the past — and not glass filters — behind the lens?
As they say in Shakespeare in Love, “It’s a mystery.” As Jon Ercole, AC Extraordinaire used to call them, BLT nets (Behind Lens, The) were lightweight, mysterious, drove rental houses mad when you used nail polish to attach them (3M “snot tape” a wiser choice), and stockings for nets were fun to shop for at Fredericks of Hollywood (Fogal Noir a favorite).
But now, Tiffen magnetic glass Rear Filters provide even more, and more repeatable, ways to define eras, distress, distort, augment, vintagize, glow, streak, flare, halate or deconstruct the image that the original lens designers spent years perfecting :)
What about shims?
Remember that flange focal depth changes by about ⅓ the thickness of a filter at the rear of the lens. Tiffen glass rear filters are approximately 2mm thick. So, you can add an approximately 0.6mm shim for a Signature Prime with rear filter — effect or clear. Tiffen is working on these shims.
If you just want a quick try-out during prep, just mark your own focus scale with chart tape.
Tiffen Rear Glass Filters for ARRI Signature Prime lenses are available from The Tiffen Company and their dealers.