Digital Video 101: Choosing the Right Camera, Part Deux

Ben Long

2

Buying a digital video camera is a lot like trying to pick out a dessert: It’s a process of trying to balance what you want with what you really need. So, just as you may want the Chocolate Truffle Surprise but be better off with the fruit plate, when choosing a digital camera, it’s important not to get wowed by all of the “high calorie” features that some vendors sprinkle on their products.

As in the third installment of our Digital Video 101 series — the first of this two-part article on choosing a DV camera — we’re assuming you’ve already chosen a video format and that you’ve probably chosen a mid-range format such as DV or MiniDV. Nevertheless, most of the issues discussed here apply to any format and level of quality.

Before buying a camera, you’ll need to examine all of its features — both those that directly affect image quality and those that have more to do with your hands-on shooting experience. Your goal is to find a camera that can facilitate the shots you need and provide the image quality required by your final master without burdening you with expensive features you might never use.

Through a Lens, Sharply
In our previous look at DV cameras, we discussed camera CCDs in detail. As we saw, the number and quality of CCDs in a DV camera is the factor that has the most influence on image quality. After CCD quality, the optical quality of the camera’s lens should be your biggest concern. Your lens influences all aspects of image quality from sharpness to color saturation to brightness.

At the consumer/prosumer level, DV cameras have fixed, non-swappable zoom lenses. Until about ten years ago, this would have been more of a concern. Over the last decade, however, computer-driven lens manufacturing techniques have improved to a point where fixed zoom lenses are now almost as good as interchangeable, “prime” lenses. Because video is much lower resolution than what you need for film, and because most fixed zooms offer a very good range from wide to telephoto, having an interchangeable lens is not as much an advantage as you might think. If swappable lenses are a concern, you’ll be shopping in the $3,500-and-up range, where there are plenty of cameras that allow you to switch between a number of high-quality zoom and prime lenses.

When evaluating a lens, it’s good to start by assessing its brightness and some of its optical properties. Because the viewfinders and LCDs on most cameras are too small to accurately assess brightness and focus, you’ll want to hook the camera up to a nice video monitor. Try to shoot a subject that is well-lit and that provides a range of colors. Consider the following:

• Is the brightness consistent across the entire image? Look for darkening in the corners of the image and try to determine if there are changes in brightness as you zoom from wide angle to telephoto. Ideally, you want an image that is evenly bright from corner to corner and throughout its zoom range.
• Look for distortion around the edges of the image. Most zoom lenses suffer from some distortion, particularly at wide angles. “Barrel distortion” makes straight lines look bowed out like the edges of a barrel while “pincushion distortion” will make straight lines appear squished inward. It’s not necessarily a problem if a lens has some distortion at the extremes of its zoom range, because you can always shoot around these. However, if you know you’ll be doing a lot of telephoto shooting, or if a camera’s distortion is particularly bad, you may want to look elsewhere.
• Is focus consistent? It’s imperative that a camera hold its focus while you’re zooming. Zoom in on a highly detailed subject (ideally, a focus test chart) and focus. Then zoom out and check to see if the image is still in focus. If a camera can’t pass this test, you should definitely eliminate it from consideration.
• Does the lens produce chromatic aberrations? Chromatic aberration occurs when the lens doesn’t focus red, green, and blue light equally. These types of aberrations are much worse in single-chip cameras than in three-chip cameras, and some cameras handle them better than others. Look for fringes of red or green in high-contrast areas, or around dark (usually diagonal) lines. Window frames, venetian blinds, or edges of chromed surfaces are good tests for chromatic aberration.
• Test the camera’s auto and manual white balance. Flesh tones are the best thing for white-balance tests, because your eye is particularly good at judging flesh colors. Under decent lighting, shoot someone’s face using the camera’s auto white-balance feature. Shoot again using the appropriate manual white-balance settings. Using the manually white-balanced footage as a benchmark, you should be able to get some idea of the camera’s auto white balance abilities.
• A poorly coated lens will have a propensity for flares and other “contaminations.” The easiest way to test for these is to point the camera at a light source (but never the sun). Move the camera around and look for smearing and flaring. Less is better.
• Finally, most manufacturers aggressively tout their cameras’ digital zoom features, which can have zoom factors as high as 200x. Digital zooms are all lousy and the only thing you really need to know about them is how to turn them off.

Getting Behind the Wheel
If the camera doesn’t deliver the controls you need to get the shot you want, great optics won’t do you much good. These concerns may seem like simple luxuries, but camera movement is part of the visual vocabulary you’ll use when shooting. If you can’t get certain movements, then you’ll be limiting your vocabulary.

Take some time to get a feel for the camera’s zoom controls. Ideally you want a control that is well-positioned and comfortable. See if you can access the zoom control from a number of positions and make sure that it provides smooth zooming with variable speeds. For maximum control you want a proportional zoom — one that will zoom faster or slower depending on how far you push the zoom control.

Hopefully your camera will provide a manual focus control of some kind as well. If it does, test for ease of use, comfort, and accuracy. Make sure the camera holds focus after you set it. If the camera has a focusing ring, check to see if it has distance markings on it; these will facilitate more complex camera movements.

Loaded with Options
Once you’ve eliminated the cameras with lousy image quality, it’s time to start studying the remaining candidates with an eye toward their overall design and feature set.

Take a good long look at each camera’s design and workmanship. Is it comfortable to use? Can you hold the camera steady? Can you shoot with it from a number of different positions and angles? Does it feel solidly constructed? Shooting video is a very tactile experience, so you want to be sure the camera feels good and provides the feedback and control you need to get your shot.

Next, take a look at the camera’s I/O options. Does the camera provide the right type of digital interface for your computer? In most cases, this will be a FireWire interface, but if you’re a higher-end user you might be looking for an SDI interface.

FireWire users should consult their editing software’s documentation for any camera-compatibility issues. For example, Apple does not recommend many JVC and Panasonic cameras for use with Final Cut Pro. Because of differences in FireWire implementations in different cameras, some features in your editing package may not work properly.

For any serious shooting, you’ll want to connect an external microphone to your camera, so look for a camera with an external microphone jack as well as a headphone jack for monitoring audio during recording.

And, of course, you’ll want to be sure your camera has a video out port for connecting to a TV or monitor. Ideally, you’ll want some sort of component output, though most low- and mid-range cameras will have S-Video or composite output (or both). A Video In port is also a nice feature as it will allow you to dub older analog footage onto DV for editing using your DV-based editing system.

Finally, there are a number of “utility” and special effects features to look for.

• Manual Features For the greatest shooting flexibility, you’ll want a camera with manual control of shutter speed, aperture, and focus. Most cameras offer fairly high shutter speeds (1/250 or 1/500th of a second) but many skimp on the slower speeds. For a more film-like look, or for eventual transfer to film, you’ll want to be sure you can force the camera to shoot at 1/60th of a second.
• Image Stabilization Skip the electronic stabilization methods and choose a camera with an optical stabilizer. To test an image stabilizer, turn it on and move the camera around at varying speeds. See if you can “trick” the stabilizer into falling behind.
• Progressive Scan NTSC and PAL video signals are interlaced, but some cameras can shoot in a non-interlaced, progressively scanned mode. These modes often provide a more “film-like” look and are ideal if you need to be able to pull better-quality stills from your video. If film is your final destination, then check with the folks at your film transfer house to see if they prefer progressive-scanned video. Finally, check to make sure that the camera’s progressive scan feature shoots at a full 29.97 frames per second.
• Widescreen The widescreen features of most cameras are really quite useless, because they simply crop the top and bottom of the normal 4:3 image to get their extra-wide aspect ration rather than shooting a wider image. Only when you get to very expensive, higher-end cameras will you get a unit with a true 16:9 CCD. If you really need to shoot widescreen and can’t afford such a camera, then you’ll need to consider some sort of anamorphic lens attachment for your camera.
• Video Standard Different countries use different video standards and most vendors make separate NTSC and PAL versions of their cameras. Usually, you’ll simply use the camera that’s appropriate for the country where you live. However, if you’re planning to transfer to film, you may want to consider buying a PAL camera. With a frame rate of 25 frames per second, PAL is only 1 frame off from film’s 24fps. Bear in mind that you’ll also need PAL monitors and decks, so this can be an expensive choice. Also, a U.S.-based film transfer house might still prefer NTSC. Be sure to check with yours before investing in a camera.
• Special Effects Most cameras come loaded with all sorts of silly effects. For the most part you can ignore these. It’s much better to shoot clean video and muck it up with effects in post-production.
• Still Quality Most DV cameras have the ability to shoot still images. However, on most cameras these images will only be at video resolution and, even on cameras that boast higher-resolutions, the images will still be optimized for a video color space. In other words, if you really want to shoot still images, you’re better off with a still camera, unless you’re willing to accept somewhat “stylized,” grungy images.

Unfortunately, there is no simple answer to the question of what is the best camera. Choosing the model that’s right for your type of work is a complex process of balancing your image quality preferences with a feature set and design that facilitates the way you like to shoot. Our advice: If you find the process too frustrating, go have a nice dessert. You’ll feel much better.