Controlling and manipulating the light (that enters the lens of your camera) | B&H Photo Video Pro Audio
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Controlling and manipulating the light (that enters the lens of your camera)

By Antonio Tibaldi

Film director Antonio Tibaldi takes a look at the Chrosziel AC-450-EX1K2 Matte Box with French Flag (and optional side-wings) for the Sony PMW-EX1, and at a selection of Tiffen 4x4 and 4x5.650 filters.

Antonio follows Lauren hand-holding the EX1 with Chrosziel AC-450-EX1K2.

This review is based on a series of tests, conducted in a studio using tungsten lights, and in different exteriors with available light. Chuck Gomez www.gomezcamera.com, a graduate cinematography major at CUNY's Media and Communication Arts who works in the film and video industry as camera operator and AC, assisted me. Lauren Lo Giudice, www.laurenlogiudice.com a New York-based actor, was our model.


WHY A MATTE BOX?


A video camera with a matte box "looks" cool, but what does a matte box actually do?

At the most basic level it extends your ability to control and modify light prior to it entering the camera's lens: It allows you to flag and block errant light from causing unwanted lens flares. The French flag (included in the kit) and side-wings (optional) enable you to further keep light off the lens.

Chrosziel AC-450-EX1K2 with French flag and optional side wings

The lightweight support rods with the follow focus system are particularly well-suited for the Sony PMW EX1. As some readers may know, the EX1's Fujinon 14x zoom lens sports a proper focus barrel (with ft. and meter readings) that "stops" at infinity and at the macro end.

This means that you can copy and report the ft/m settings from the barrel of the lens to the white ring of the follow-focus knob. This allows you to pull focus accurately while operating. The position of the follow-focus knob, right below the flip-out screen, is particularly well-suited for this use.

Another interesting characteristic of the Chrosziel AC-450-EX1K2 Matte Box is that while it adds 2 lb of evenly-distributed weight to the camera, it allows for a better "handheld" grip.

The focus knob enables you to better handhold the camera at a high-angle.

As EX1 owners know, the rotating hand grip protrudes to the right, throwing the camera off balance to the left. The focusing knob of the follow-focus system, because of its far-left placement, compensates for this: by holding the camera with the right hand on the hand grip and the left hand on the focusing knob, you have now a well-balanced camera in your hands. The focusing knob, rugged and sturdy, allows you to do this.

… at medium height,
... and at a low angle.

THE FOLLOW-FOCUS SYSTEM

When shooting in situations where you are trying to be transparent and not draw any attention, the "coolness" of the matte-box rig might become a negative. You can, of course, not use it in those situations and remove the entire unit, but once you get used to pulling focus and hand-holding the camera with the unit on it may feel strange to have the "bare" camera in your hands. With a simple twist of the quick-lock mechanism knob that anchors the matte-box system to the 15mm lightweight support rods, you can easily slide off the matte box, leaving the rods and follow-focus system mounted. You can then remount the original Sony lens hood. I have found this setup quite useful and efficient in documentary situations.

Another consideration is that the EX1's "original" lens hood provides good protection from unwanted lens flare, and the eyebrow lens cap makes it fast and easy to start shooting (without having to remove a lens cap, which can be easily lost or misplaced!).

without matte-box
with matte-box

When you do have the Chrosziel matte box mounted, one of the concerns is that you no longer have a lens cap. Dust and dirt easily accumulate on the surface of your filter or lens, and you want to avoid that. "Closing" the matte-box by folding the French flag over the matte box is what I have done in the past (I owned a Panasonic DVX 100 with a clip-on Chrosziel matte box), but that doesn't give full dust-protection, and the camera (with the French flag folded over the matte box) will no longer fit in your carrying case. To solve this problem, 16x9 Inc., Chrosziel's official importer in the US, offers a convenient matte-box cover, easy to put on and remove.

with mattebox cover in 16x9 Grab & Shoot bag

Another interesting solution offered by 16x9 Inc. is the Grab & Shoot camera bag, designed to transport the camera with the matte box securely in place. The top front tongue unzips for quick access to the camera, which can be secured to the bag by a snap-on strap. A second compartment is designed to hold lens adapters, filters, batteries, a charger, and other accessories. Its 23x11x11" dimension allows you to carry the camera onto most commercial flights. I found the bag well designed, and for the price ($189), a good buy. As the EX1 (with additional batteries, matte box, charger, filters, etc.) is a relatively heavy package, I felt that the shoulder strap was undersized and strained the shoulder. I exchanged it for the Suede Shoulder Strap of my PortaBrace carrying bag, which now acts as my accessory bag, and carries less weight. That solved the problem. A wide selection of heavy-duty shoulder straps is manufactured by PortaBrace and can be purchased separately.

FILTER TRAYS:

The AC-450-EX1K2 Matte Box has two filter holders: one 4x5.65 fixed, and one 4x4 which rotates 180°. Because of the placement of the microphone and flip-out screen of the EX1, The 450-system requires users to load the truncated filter trays from the bottom. You can still rotate the filter stage, but from the bottom. This gives the filter stage approximately 1mm clearance from the viewfinder. In the event the filter stage still touches the viewfinder, you may need to center-adjust the lightweight support. Between the two rods, you will find a hex screw. Loosen the screw, align the lightweight support, and secure. When done properly, the matte box will be centered to the lens and give you the 1mm clearance from the viewfinder.

It is a rather tight squeeze for the matte box unit to fit onto the EX1, which has obviously not been designed with this particular accessory in mind. Nonetheless, Chrosziel has done a good job in custom-designing a matte box that, once properly installed, fits nicely. At first it feels unusual to install the filter trays from the bottom, but after a few days you become accustomed to it. I have placed a strip of black gaffer's tape over the back of the flip-out screen, so that were it to touch the ring of the filter stage, it wouldn't get scratched. I admit that it is an overprotective, unnecessary precaution: once properly installed, the 1mm clearance is sufficient.

OPTICAL FILTERS:

Whether you shoot documentary or fiction, outdoors or indoors, the matte box gives you the option to use filters which greatly enhance your ability to control your images. A great deal can be fixed in post production, but making creative choices at the moment of exposure is different from later color-correcting your image (which you will still want to do with a filtered image).

4x4 or 4x5.650 glass filters slip into the filter trays, which then can be dropped into the 2 filter stages of the matte box. Because you are adding a layer of glass in front of your lens, you will want to use only high-quality, reliable filters. Tiffen is a company that has been manufacturing filters for more than 70 years, and has served multi-million dollar Hollywood productions for decades. It manufactures its filters using ColorCore™ technology, a closely guarded proprietary process that entails permanently laminating the filter material in between two pieces of optical glass that are ground flat to tolerances of a ten-thousandth of an inch. The ColorCore™ process allows control of color and density with much greater accuracy than typical dyed-in-the-mass filters.

Because video—even HD video—has relatively narrow latitude of exposure, gradient filters are useful in managing the brightness of the sky in wide, establishing shots.

No filter – the sky is overexposed and becomes completely white.

Using a CLR/ND 1.2 Graduated Soft Edge filter enables you to gradually add 4 stops of density to the top part of your image. For a similar, yet less dramatic effect, you may use a .9 or .6 CLR/ND soft edge. If you are using a telephoto lens, you would use a hard edge grad filter for a similar effect.

Once you have controlled the density of your image, you may want to "paint" it with the multitude of color grad filters available. The CLR/Tobacco 2 Soft Edge GRAD adds nice warmth to the image, giving it a sunset, yet ominous quality.

The CLR/Tangerine 2 Soft Edge GRAD does a similar service to this image, possibly a less dramatic, more realistic sunset effect.

For a more extreme, almost mono-chromatic look, I used a solid Complement Amber 1 filter. (This image was obtained with a CLR/Tobacco 2 Soft edge Grad filter and with a Complement Amber 1 filter).

In a similar fashion you could paint this whitish, overcast sky blue, using Cyan (2 or 3), Blue, or Cool Blue GRAD filters.

Polarizing filters literally polarize the light to eliminate reflections on glass and water surfaces while retaining sub-surface details. Neither of these effects are possible with after-the-fact plug-in filter systems, which can only provide filter effects, not true light filtration.

This is with the polarizer filter rotated so that it does not affect the reflection on the glass.

Here the polarizer has been rotated to greatly diminish the reflection.

At certain angles shooting a blue sky, the polarizer filter will dramatically enhance contrast—an over-exposed, otherwise washed-out sky will have a deep-blue look.

CONTRAST AND DIFFUSION FILTERS

The shift from Standard Definition to High Definition video is an invitation to explore the possibilities offered by contrast and diffusion filters. The extreme sharpness obtained with a 1920x1080-pixel image can become problematic if you are shooting an interview or a face in close-up. Its extreme sharpness intensifies the blemishes and the imperfections in skin tones. It's almost as if, in some situations, you are fighting against the sharpness of HD.

In a hard lighting situation, HD can be unforgiving.

812 'warming' filter is very popular and adds warmth to the image. Ideal for close-ups, indoors and outdoors, in shade on a sunny day.

Glimmer glass 1 softens the image very slightly—see the difference with image below (no filter). It's a filter developed by Tiffen to "make people look their best." The filter has a silver sparkle that is noticeable when you are in front of the lens. It has been said that it gives confidence to your subject. I asked Lauren if she noticed it, and she said: "Yes, absolutely." I don't know if she was saying that to please me, but nonetheless, the filter does soften fine detail and it adds a slight glow to the highlights. I quite like it.

Gold diffusion ½ suppresses facial blemishes while maintaining a clear, focused image. It also adds that 'golden' warm element (all of these filters come in different gradations, from 1/8 to 4 or 5). With contrast and diffusion filters, I personally like an image that doesn't seem like it has been filtered in any way.

Here, a CLR/Tobacco 2 Soft Edge GRAD filter is positioned vertically and alters the color and density on the left portion of the image.

Same as above, except using a CLR/ND 1.2 Grad filter. Because the zoom lens is at a telephoto setting, Hard Edge instead of Soft Edge is used.

The Straw 1 filter brings overall warmth to the image without affecting its contrast.

A similar effect, more on the red spectrum of 'warmth,' is obtained with the Coral ¼ filter.

No filter

Black Pro Mist ¼, a very popular filter for video, lowers the contrast and diffuses some of the sharpness without altering the chroma.

no filter

Pro-Mist 2 filter offers quite a dramatic haze effect with glowing highlights. This filter, at a 2 gradation, is probably too noticeable for the above situation, but used at night, with street lamps, it's quite effective. It makes for a misty-looking night.

Lauren was wearing a tangerine-colored sweater, so we decided to play a little with it.

By using a Complement Amber 1 filter, her flesh tone and the color of her sweater are enhanced, while the overexposed sky remains white.

By adding a CLR/Tobacco 2 Soft edge, some warmth in the upper portion of the sky can be detected. That balances the chromatic characteristic of the image quite nicely.

Lauren changed her top and we tried the same thing with Graduated Complement Blue 1 Glass Filter

 

I would have needed a CLR/Blue 4, instead of 2 in order for the blue sky to creep into this image.

These are just a few examples of what you can achieve and how much you can vary and improve your image using a selection of filters. Take a look at the impressive selection of filters offered by Tiffen and you begin to get a sense of the vast range of image control at your fingertips. Once you get used to having a matte box with follow-focus, which enables you to slide in any of these filters, you realize how empowering it is to have this additional tool for controlling your image. While you decide about buying a matte box, there are several things you should consider. First is the build quality: is it made of metal, plastic or some sort of composite construction? How will it hold up in the field? Second, to ensure optimal results, you'll want to choose either a 4x4 or 4x5.650 filter tray size for a camera with a 16:9 aspect ratio. Also, you'll want to make sure that the filter trays are solid and secure, allowing you to move confidently behind the camera without fear of damaging your expensive glass filters. If you find yourself routinely fighting lens flares and desire further control of your image other than with white balance and f-stop settings by adding filtration to the front of your camera, you should consider investing in a good-quality matte box to give you this additional layer of control. I have thoroughly researched matte boxes and filters and have settled with Chrosziel and Tiffen for their reliability and high-end manufacturing standards. They are pricier than most other options, but as common wisdom frequently suggests, you do get what you pay for.

No color corrections were made to the photos in this article—the images were white-balanced without filter, then the filter was added (without re-white-balancing).

ANTONIO TIBALDI

Has written and directed 5 feature films. Credits include ON MY OWN (Alliance Atlantis), LITTLE BOY BLUE (Warner Bros.), KISS OF FIRE (Miramax). He is also an active documentarian. As cameraman and editor for UNTV (United Nations TV) producer Michele Zaccheo he has traveled to remote parts of the world to put the spotlight on some of the world's most underreported stories. His recent assignments have taken him to Indonesia, Guatemala, Honduras, Colombia, Ecuador, and Mexico. He teaches Film and Video at the Media & Communication Arts department of CCNY (City College New York).


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