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While the ability to record video has been built into compact digital cameras for years, as recently as two years ago there were no digital SLRs with video capability. That all changed in the last quarter of 2008, when Nikon introduced the D90 with the ability to record 720p HD video, and Canon soon followed with the EOS 5D Mark II and its ability to record 1080p full HD video.
Today (as of this writing), we have 11 digital SLRs that can also record HD video with more on the way. And along with the video-capable DSLRs, we’ve also seen the recent arrival of SLR-like digital cameras featuring DSLR-sized image sensors, interchangeable lenses and video capability, but with simple electronic viewfinders replacing the SLR’s bulky and complex mirror box and pentaprism viewfinder (see the sidebar “DSLR-Like Cameras With Video Capability”).
What all this means to you as a nature and wildlife photographer is a new dimension to the way you can record the outdoor scene: with motion—and sound. This opens up great creative opportunities, from showing wildlife behavior to the power of waterfalls. Video-capable DSLRs let you produce top-quality still photos and HD video, all with a single, compact unit.
HD Video Primer
Digital still images are recorded one at a time, each consisting of pixels. For example, a 12.1-megapixel Nikon D3S produces still images measuring 4256×2832 pixels (you can select lower resolutions when desired).
Digital video images consist of a series of horizontal lines scanned across the screen, commonly at rates of 24 or 30 image fps. For standard-definition (SD) digital video, each image frame consists of 480 horizontal lines, each 640 pixels wide. High-definition (HD) digital video frames have 720 lines, each line 1280 pixels wide. Full HD digital video frames have 1080 lines, each 1920 pixels wide.
There are two ways video images can be scanned. In progressive scanning, the entire frame is scanned at once. In interlaced scanning, each frame is produced in two scans, first the odd-numbered horizontal lines, then the even-numbered lines. Progressive scanning is better for moving subjects, since such subjects will have moved a bit between the odd-line and even-line scans with interlaced scanning. All current DSLRs with video capability employ progressive scanning. Progressive and interlaced are indicated by a “p” or “i” after the resolution figure: HD video is 1280x720p, or just 720p, for short.
Some DSLRs shoot video at 24 fps, some at 30 fps. The motion pictures you watch at the local theater are filmed at 24 fps, and some video photographers feel video shot at that rate looks more “cinema-like.” The faster 30 fps rate is standard for video and better handles moving subjects. Some video DSLRs also can shoot at 60 fps, which is even better for clips that include moving subjects. A few video DSLRs let you choose 24 or 30 fps for full HD video. (Note: These frame rates are for the NTSC video system used in the U.S. European countries use the PAL system and video frame rates of 25 and 50 fps.)
DSLR Vs. HD Camcorder
Designed specifically for video recording, HD camcorders offer advantages over DSLRs, which were designed for shooting still images. Camcorders are more comfortable to hold in shooting position for long clips (although video recording is best done from a tripod, as any camera movement will show in the video). Camcorders have AF systems and power-zoom lenses that operate silently and smoothly, so you get smoother zooms and no camera noise when using a built-in microphone. (While DSLRs have excellent phase-detection AF systems for still photography, they use slower contrast-based AF for videos, and built-in microphones will pick up the sound of the AF motor, aperture mechanism, stabilizer, etc.) Camcorders have eye-level electronic viewfinders, which are more convenient for handheld work than the DSLR’s live-view LCD monitor, and they have better sound capabilities.
On the other hand, HD camcorders can’t shoot first-rate still images, and even the pro models have relatively tiny image sensors. The smaller the sensor, the smaller the pixels for a given pixel count, which adversely affects image quality, especially at higher ISO settings. And the tiny sensors mean the cameras have to use much shorter focal lengths to provide a given field of view than a DSLR with its larger sensor. Shorter focal lengths produce more depth of field, and one big problem with camcorders is limiting depth of field for a “cinematic” look and selective-focus shooting—no problem with a DSLR and its big sensor.
DSLRs also accept a wide range of interchangeable lenses, including fisheyes, superwides and tilt-shift optics.
Bottom line: If you want to shoot only videos, get a camcorder. If you’re a still photographer looking to expand your creative horizons, get a video-capable DSLR.
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Canon EOS 7D
Canon’s EOS 7D features an 18-megapixel CMOS sensor, 8 fps shooting (for up to 15 RAW or 126 Large/Fine JPEGs using a UDMA CompactFlash card), a sensor-dust remover, ISOs from 100-6400 (expandable to 12,800), a 100% SLR viewfinder and a 3.0-inch, 920,000-dot live-view LCD monitor, and more.
The 7D can shoot 1920x1080p full HD video at 30, 25 or 24 fps, and 1280x720p HD and 640x480p SD video at 50 or 60 fps. A live-view/video switch/button control makes it simple to start shooting video. You can set shutter speeds (1⁄30 to 1/4000 sec.) and apertures manually, if desired, or let the camera do it (with video, shutter speeds in the 1⁄30 to 1⁄125 sec. range produce the smoothest motion). You can autofocus before or (via contrast-based AF) during video recording. The 7D can record up to 4 GB of video in a single clip; that works out to about 12 minutes of HD or 24 minutes of SD video. You can shoot one or more still images at anytime during a video; if you do, the video will be disrupted during still shooting, and a one-second still frame will appear at that point in the video.
The built-in microphone records mono sound; an optional 3.5mm stereo mic can be connected for stereo sound. Videos are recorded as MOV files with MPEG-4 AVC compression; audio is recorded in Linear PCM.
Canon EOS Rebel T2i
The new T2i offers the same basic image sensor and image quality as the 7D in a more compact package for about half the cost. The T2i shares the 7D’s metering system, but the 7D has a more advanced AF system.
While it provides the same video features as the 7D, the T2i adds a new Movie Crop mode, which provides 7x magnification by cropping the image directly from the CMOS sensor at full SD resolution—handy when you can’t (or don’t want to) get close enough to shy or dangerous subjects. The T2i is also the first EOS model to accept new high-capacity SDXC memory cards, which can hold more video footage.
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Nikon’s D300S adds HD video and quicker operation to the popular D300. The 12.3-megapixel camera can shoot excellent full-res images at up to 7 fps; it provides excellent AF performance on fast-moving subjects like birds in flight and quick access to AF modes and areas via switches. There’s a 3.0-inch, 920,000-dot LCD monitor with live view (and a handy live-view button for easy access), effective Active D-Lighting to tame high-contrast scenes, a sensor-dust remover and more.
The D300S can shoot 1280x720p HD video, plus 640x424p and 320x216p video, all at 24 fps. In Handheld mode, you can prefocus (using phase-detection AF) before recording and the camera sets the aperture; in Tripod mode, you can autofocus (via contrast AF) during recording and also can select the aperture. Note that the built-in microphone will pick up the sounds of the AF and aperture motors—as with all video DSLRs, it’s best not to use AF or change apertures during a clip when using the built-in microphone. You can record up to 2 GB of video in a single clip (5 minutes of 1280x720p, 20 minutes of 640x424p or 320x216p video).
Sound recording is in mono via the built-in microphone, or you can connect a 3.5mm external stereo mic for stereo sound. Videos are recorded in AVI format with Motion JPEG compression.
The first video DSLR, the Nikon D90 features a 12.3-megapixel CMOS sensor similar to the one in the D300S, but a couple of generations earlier and with less processing power. Still, it produces excellent image quality (DxO Labs’ DxOMark sensor-rating website, www.dxomark.com, rates its still images tops among APS-C-sensor DSLRs, in fact) and has a simpler AF system that still can handle birds in flight surprisingly well.
The D90 can shoot 1280x720p HD video, plus 640x424p and 320x216p video, all at 24 fps. You can lock in the aperture before beginning recording and establish focus via contrast-based AF before, but not during, recording.
A built-in microphone records mono sound, and there’s no jack for an external stereo mic. The D90 can record clips of up to 5 minutes in HD and 20 minutes in SD, but no clip can exceed 2 GB. Video is recorded in AVI format, with Motion JPEG compression.
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With a rugged moisture-, dust- and cold-resistant (and very compact) body and a host of features, the K-7 could serve a working pro outdoor photographer very well, but it comes with a near-entry-level price. Among those features are a 14.6-megapixel, APS-C-format CMOS sensor, a 3.0-inch, 921,000-dot LCD live-view monitor, built-in sensor-shift shake reduction that works with all lenses, a built-in sensor-dust remover, three-frame, in-camera HDR, mirror prelock, automatic lens correction (for distortion and chromatic aberration, with DA lenses) and two RAW formats (Pentax’s PEF and Adobe’s “universal” DNG).
The K-7 can shoot 1280x720p HD video, plus 1536x1024p and 640x416p video, all at 30 fps. Operation is simple: Rotate the mode dial to the movie icon, and press the shutter button to start shooting; press again to stop. The camera controls ISO and shutter speed in video mode, but you can lock in a desired aperture before starting to shoot.
A built-in microphone records mono sound, or plug the optional stereo mic into the provided 3.5mm jack. You can’t shoot a still image during video recording. Videos are recorded in AVI format with Motion JPEG compression.