Monday, August 11, 2008

Petroff 4x4 Mattebox on Sony EX-3

I've been too busy enjoying my new Sony PMW-EX3 even to post!

There has been some chatter on the discussion forums that the Sony EX1, EX3 and indeed even Red exhibit an unfortunate trait common to CMOS cameras-- poor rejection of the IR spectrum. This could potentially result in color shifts or inaccurate reproduction of colors.

I'll be testing both for this site as well as for a future article on the EX-3 the IR rejection capabilities of the B+W True-Cut 750 IR filter. This new filter is touted by Schneider Optics to be superior to its earlier 486 and 489 IR cutting filters, reducing the potential for a greenish tinge which could potentially occur with the 486 and 489.

The IR 750 is currently only available in a 4x4 filter and that meant using a mattebox.

The Petroff 4x4 has long been my favorite and courtesy of Petroff, you see a Petroff 4x4 mounted to the EX3 using a lens mounting ring which Petroff developed for the EX1. Petroff had not yet tested the EX3 but I was convinced that there would be no issue with fit since the lenses are identical other than the interchangeable feature of the EX3. I was right.

The unit I am testing here is a two stage 4x4 model with optional side wings and a French flag. It is mounted with the Zacuto baseplate and rod system, my unqualified favorite plate and worth every penny.

Why do I like this product so much?

It is sturdy yet lightweight. The mattebox is made from a combination of metal and virtually-indestructable polymide. It has flexibilty while also being able to bend without feeling that you are permanently bending metal.

It is modular and can be assembled/disassembled without tools. You can add or remove stages, insert/remove filters, assemble/disassemble the mattebox and not have the need of a screwdriver.

Each stage can rotate or be locked in place. In the case of the IR 750 filter, I would not want to rotate the stage. A 4x4 polarizer would be an entirely different manner. Those same thumbscrews over which the lock fits are also the screws you would loosen to remove the filter holder. Then it is a simply matter to drop the filter in the holder and return to the mattebox, tightening the screw.

Note one concern with the design of the EX1/EX3. That infernal (and, in my opinion useless) built-in mike protrudes too far forward. It does partially block the thumbscrew in the stage closest to the camera. It is not a major issue but a bit of an annoyance requiring deft small fingers or a needle-nose plier to operate the screw. I suspect it might be possible to design a donut to extend the entire assembly slightly. Petroff does manufacture a "universal" mattebox designed for Sony HDV cameras where the built-in mike constitutes a more significant issue. EX owners might want to consider this universal model.

In this shot, note how tightly the mattebox components fit together and how securely the lens adapter, large lens mount screw and rod attachment both hold the mattebox together as well as secure it to the Zacuto baseplate.

No light leaks, no wobbling, secure snap in filter holders give the user of this mattebox complete confidence that it is doing what a mattebox is supposed to do-- light control, hold filters, and fit securely to the supporting rods.

The Petroff mattebox accomplishes all of these tasks and then some.

The P44 two stage as shown lists at $1370. Follow-focus is also available.

Check out the full product specs and product line at

Check out the baseplate, rods and tons of other related accessories at Conveniently enough, Zacuto is also a Petroff dealer.

That's the mattebox part of this installment. Will start shooting with the filter in the coming days to determine whether the IR problem is pervasive or just infrequent.