Lens Filters and Adaptors Buyer's Guide

Filmmakers and camera operators can take advantage of a wide variety of filters that attach to their cameras, which can be used to help balance the color in a shot, or protect the lens from scratches. Special effects filters can also be used creatively, to help set a mood or create a unique look for a video project.

Filters

The most common filters everyone should use are designed to protect your lens from scratches and daily wear-and-tear, such as UV and clear options. These filters can be either glass or plastic, though using glass is highly recommended with any high definition camera, as plastic filters can show scratches and nicks in your footage. There are two basic ways for a filter to attach to your camera: the lens screws on directly or is placed in a matte box or holder. Both types can span the gamut of what they can do, be it protection, balancing color, managing light, and for creative use. Manufacturers include Tiffen, B+W, Hakuba, Promaster, Formatt, Sunpak and others.

Color Balance

There are several varieties of color balance filters, including those that are true color temperature blue or orange (CTB and CTO), rated at 5600 kelvin (k) and 3200k, respectively. Both film and digital cinematographers often use these filters in place of electronic white balance. For example, if you're shooting outside, the light's color temperature is normally 5600k, so you'd use a CTO filter rated at 3200k. There are also variations to the blue and orange color balance filters, for different color temperatures.

Neutral Density

While most cameras include built-in neutral density (ND) filters, there are ND filters that come in a variety of light-to-dark options that go beyond just the standard two or three step internal filters found in some cameras. They can be stacked to add even more options, which helps with your shutter control for better depth of field difference.

Polarizers can also be used in conjunction with ND filters to cut light further, so you're not adjusting the aperture or shutter, unless you choose to. Polarizers have two main functions: to cut down glare and to eliminate reflections in windows or water, allowing you to shoot clearly through to the subject you're trying to capture. They have an outer ring that turns, and depending on the angle where the glare or reflection comes from, if you turned the free lens 90 degrees one direction, it blocks out all vertical light and spinning the other direction blocks out the horizontal light. Polarizers will also take a dull gray sky and brighten it up giving you the true blue you're looking for. B+W sells some nice polarizers and ND filters in various sizes, with prices around $50 to $100.

Special Effects

If you want to get creative, there are all sorts of special effect filters available, allowing you to subtly or radically change the color, lighting, add a soft focus, or create a vignette in your shot, giving it a classic look with a soft shadow in the corner. Star filters can make light sources appear as stars, while a center spot will put your subject in focus in the center, while diffusing the area around it. Many Hollywood blockbusters use color special effects filters to help create specific moods or atmosphere. You've probably seen the films that rely on blue filters, like Terminator 2: Judgment Day, or tobacco filters to give the film a golden look. Regardless of it's name, a tobacco filter isn't meant to give a smoky look, it's brownish color will give your video or film a golden look and is great for bringing out the colors of a sunset. Both practical and special effects filters are available as graduated filters, or grads. A grad tobacco filter, for example, will have the golden color at the top, then gradually move to clear either midway or near the bottom of the filter. This helps to create a specific look, or block light via ND, of the sky, while keeping the ground clear. Grad filters can also be 50/50, solid and clear.

If you're shooting for glamour , you may want to consider a Pro-Mist filter, which helps create a nice soft, diffused look. You can choose Pro-Mist filters that are light or heavy on the diffusion, plus warm and black to change the color and blacks slightly, too. Tiffen offers a variety of Pro-Mist filters, starting around $100.

Adaptors, Matte Boxes and Step Up/ Step Down Rings

Adaptors are used to attach filters to your camera's lens, and they range from small and affordable filter-holder systems, such as those from Cokin, Pentax, OP/TECH USA and others, to the larger and more expensive matte boxes from Cokin, Schneider Optics, and others. Matte boxes range in prices from around $300 into the thousands, while simple adapters can cost as little as $15, not including the filters, and go up to hundreds of dollars, depending on their use.

Matte boxes are used to help cut down on the Sun or any light source that can cause an unwanted glare into the camera's lens. While director J.J. Abrams loves to include lens flares in his films, filmmakers and camera operators probably prefer not to. The matte box is bigger than a standard lens hood found on many video cameras, and uses removable flags, or wings, to block the light. These flags vary in size, which is advantageous if you can't move the camera too far from a positioned light that is giving you glare problems.

A matte box can hold square filters, such as those measuring 4 x 4 or 3 x 3-inches, or larger. You place it into a filter holder and slide it into place in front of the lens, but behind the matte box. You can use several filters, known as stacking, such as a polarizer and a special effect filter, but watch out for vignetting (distorted edges) and light getting cut down unintentionally.

Step-up and step-down rings allow you to use certain round filters that don't fit your lens. If you have a larger filter, say a 72mm, and your lens is smaller, you can use a step-up ring to fit the filter. A step-down ring is used if your lens is larger than the filter. Be careful, because an unwanted vignette may occur with thicker filters. Heliopan carries a line of step-up, step-down rings, in addition to filters.

Conclusion

Camera filters are a good investment for any camera operator or filmmaker who is serious about capturing unique and cool looks with a special effect filter, balance color temperature, or to protect their lens with a UV filter. In addition, there are also adaptors and matte boxes that go along with using filters and offer protection from glare.

Sidebar: Lens Controllers

• Lens controllers are designed to control the speed of the zoom, iris and focus on a camera's lens, and it does it smoothly, along with controlling the record start and stop. It can also switch focus and iris to auto or manual.
• The advantage of using a lens controller is to avoid camera shake when you perform those functions, and helps to get professional results.
• The lens controller may attach to the arm of a tripod, and connect to the camera. You easily control the zoom, focus, iris and record start/stop on the unit.
• Lens controller manufacturers include VariZoom, Manfrotto, and Sign Video, and many others are geared toward specific cameras, such as the Sony PMWEX1R.
• Zoom Commander Pro by Sign Video costs $180, and is an excellent addition to any camera operator and independent filmmaker's toolbox.

Sidebar: Virtual Filters

Tiffen, among a few other companies, offer virtual lenses that you "apply" to your scene in post production. The Tiffen Dfx digital video filter products have many special filters and you can test the effects online. You'll find virtual filters from black and white to fog, ice, streaks, depth of field, noise reduction and sunset/twilight filters among many others. Their latest version, Dfx v3, has a key light filter that will gently highlight a particular spot in your scene, seeming to make the subject stand out from the rest. Check it out.

Click here to download a PDF of Videomaker's Lens Filters and Adaptors Buyer's Guide

Heath McKnight is Senior Writer at TopTenREVIEWS.com and a filmmaker. He co- wrote VASST's two best-selling books on HD production.