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Harnessing the Power of the EOS 7D’s Video System
The new Canon EOS 7D is not the first digital SLR to incorporate video recording capability, but it’s arguably the world’s most complete “HDSLR” at the time of its introduction. Starting with its CMOS imaging sensor — far larger than the sensors in most high-end professional video cameras, even though it’s not a full-frame sensor — and progressing to its range of features, this camera takes high-quality video recording capability in an SLR and moves it to a new level. This article will serve two purposes: to explain the powerful new EOS Movie features found in the EOS 7D, and to give insight into their use in real-world situations. Whether you’re a serious video shooter who needs the outstanding low-light quality of EOS Movie recording, or a traditional still shooter who wants to record video for a web site, the EOS 7D’s tools will give superb flexibility.
One of the several design improvements of the EOS 7D Includes a dedicated switch and START/STOP record button for Movie Mode.
New EOS Movie features in the EOS 7D:
30 fps or 24 fps?
This is a major question for many video shooters, but now you’ve got the choice right on the EOS 7D’s video recording menu. If you’re shooting at full 1920x1080 HD, here are some points to consider.
The case for 30 fps: 30 frames per second is the traditional recording speed for material to be used on-line, whether on popular web sites like vimeo.com™ or youtube.com™, or on another commercial site. The true EOS 7D recording speed at an indicated “30 fps” is actually 29.97 frames per second — precisely the TV standard in North America. Thus, it’s well-suited to material you intend to transfer to DVD or otherwise display on a typical standard-definition or HDTV. Material to be recorded for TV commercials or any other video that will be potentially be directly broadcast on TV may be better suited for recording at the 29.97 fps rate.
You can select your Movie Rec Size in the dedicated menu (only accesable when the EOS 7D is in Movie Mode)
Additionally, if you’re recording moving subjects or will be significantly moving the camera, there’s a bit less tendency for a choppy “strobe effect” in finished video at the faster 30 fps.
The case for 24 fps: You’ll hear some experienced video shooters say that 24 fps generates more of a “film look”, meaning that certain types of motion appear more natural to your eye and brain. However, this slower frame rate can sometimes produce movements that are less smooth than when captured at 30 or 60 fps. This can be an issue if you anticipate frequent subject movement, or camera movement (think of “reality” TV shows as one example of this type of shooting where there is constant movement of both subject and camera). This also presupposes slower shutter speeds, around 1/50th of a second.
Traditional movies, shot on actual film, are shot at true 24 fps. Video from an EOS 7D, taken alongside actual film (which we anticipate will be done from time to time in Hollywood studios) is shot at an actual rate of 23.976 fps; it would have to be speeded up very slightly in the computer to exactly match film — normally, very easy to do.
Exposure control for EOS Movies:
The EOS 7D is ready to shoot video with either full manual control, or totally automatic exposure control. There’s also an interesting “hybrid” method: in manual exposure mode, set a particular shutter speed and lens aperture (something realistic for the lighting you’re in; you can’t expect to shoot indoors at 1/4000th second at f/22!). Now, if you set ISO to “Auto”, the EOS 7D will adjust the ISO sensitivity anywhere from 100 thru 6400. And it will retain the shutter speeds and apertures you’ve set.
Automatic exposure: This is the default method of video shooting with the EOS 7D. With the mode dial set to any location other than “M”, when you shoot video, the camera will automatically select lens aperture and shutter speed, as well as ISO, based on the light in the scene. Exposure will adjust automatically, on the fly, if the light changes as you move the camera during a shot.
Keep in mind that even though the Mode Dial has settings for Tv (shutter-priority automatic) and Av (aperture-priority automatic), these are for still image shooting only. Once you begin shooting video, these will simply revert the camera to totally automatic, programmed exposure — the camera always picks both video shutter speed and aperture.
Exposure Control during automatic video shooting: One issue video shooters encounter with auto exposure is that if the camera is panned to follow a subject, or if it moves from a light-colored subject to a darker one (or vice-versa), the overall exposure in the scene often changes. With the EOS 7D, this is easy to prevent, using the AE Lock feature. The rear button with the asterisk icon can be pressed either before or during shooting, and exposure locked in-place at that moment. An asterisk appears in the information strip below the scene on the LCD monitor, reminding you that exposure is indeed locked. To unlock it, don’t press the AE Lock button again. Press the AF point select button immediately to the right, and the asterisk icon will disappear.
Exposure Compensation can also be applied, to intentionally lighten or darken video footage. The EOS 7D expands the available adjustment range; it’s now up to plus or minus 3 stops (the previous EOS 5D Mark II, for example, was limited to +/- 2 stops during video recording). It’s applied with the large rear Quick Control Dial. Remember that while it’s absolutely possible to turn the Quick Control Dial during live recording, if you’re using the built-in microphone, it probably will pick up the “click” sounds of the dial as you turn it.
Manual Exposure control: One major advantage serious video shooters cite about manual exposure control is that once it’s set, if the camera is moved or the subject tone changes, exposure remains constant. In many cases, this is a very desirable characteristic — especially for video where frequent panning with a subject, or camera movement is anticipated.
Furthermore, of course, it’s simple for the experienced shooter to set an intentionally different exposure, such as deliberately darkening a scene for a more dramatic look, or intentionally lightening a heavily back-lit scene. Again, once set, the shooter doesn’t have to worry about the camera “correcting” the exposure, which can sometimes happen with automatic exposure.
Video Shutter Speeds: The EOS 7D allows the user to set any shutter speed from 1/30th second (1/60th if set to 50fps or 60fps) thru 1/4000th second. Canon USA has produced a brief article about the effect of video shutter speeds on the Digital Learning Center. You can read it HERE.
Apertures and depth-of-field: One of the big changes that EOS Movie brings to the realm of video is a different “look” than a typical professional video camera produces. Even though the imaging sensor in the EOS 7D is not a full-frame sensor, as we see in the EOS 5D Mark II, for instance, the 7D sensor is still much larger than the sensor used in nearly all video cameras under $30,000. An immediate result is far less depth-of-field — it’s much easier to throw a foreground and background out of focus, for creative effect, with an EOS video than with conventional camcorders.
Selective focus becomes an easily attainable look in your video, without necessarily having to resort to exotic, long telephoto lenses to throw backgrounds out of focus.
Obviously, lens aperture choices enter the discussion here. Beyond what’s necessary for simple exposure control, aperture setting becomes every bit the same creative decision as it would be in still photography. Keep in mind that this tendency for narrow depth-of-field in EOS Movie imagery will be apparent, to some degree, even in wide-angle video images. If you truly need lots of sharpness, foreground-to-background, you often will need to stop the lens down deliberately to apertures like f/11, f/16 or possibly even beyond. Manual exposure mode becomes ideal for this type of shooting. Even then, depending on the lens’s focal length and how close you are to the subject, it may be impossible to get total sharpness in your backgrounds.
Still images during video shooting:
Unlike a typical video camera, EOS Movie means you don’t have to sacrifice quality to get great still images, even if you’re shooting video. Obviously, with nearly any video footage, a “frame grab” can pull a still image from actual video files. But these are limited to about 2 million pixels when shot in full 1920x1080 HD; they’re even lower resolution if the video setting is at 720p or 480p. And at least during automatic exposure, Canon’s EOS Movie always tries to keep video shutter speeds between 1/30th and 1/125th second, for smooth video movement on-screen. This means, however, that individual video frames of those same moving subjects can appear blurry.
With EOS Movie on the EOS 7D, however, if you press the shutter button fully during actual video recording, the camera will take a separate, still image file whatever still image quality setting is currently in effect on the camera’s menu. In other words, if you’ve previously set the camera to shoot full-resolution RAW image files, that’s what your still image will be, even if shot during live video recording.
This ability of the EOS 7D to shoot full HD video at 24 fps or 30 fps, and yet be able to shoot an eighteen million pixel still image whenever you desire, opens many creative doors — even for video producers, let alone traditional still shooters who want to add video to their “bag of tricks”.
Like with the EOS 5D Mark II and EOS Rebel T1i cameras, still images taken from the EOS 7D will be recorded as a totally separate image file on the memory card. And like other EOS models with EOS Movie capability, there will be about a 1-second pause in video recording if a still photo is taken during live video shooting (video immediately resumes, with no stoppage, after this).
Summary:
The Canon EOS 7D is arguably the world’s most advanced HDSLR camera for video recording, at the time of its introduction. Its ability to shoot full HD 1920x1080 video, along with user controls for frame rates and manual exposure, provides the video professional or creative shooter with some compelling possibilities. Add the ability to shoot at 720p HD, at a full 50 or 60 fps, and yet another avenue is opened for the advanced, creative user.
Finally, remember the possibilities in the EOS lens system, both in the EF-S lenses as well as the EF series. Some lenses, like the 50mm f/1.4 or 50mm f/1.2L, have virtually no comparable examples on the video camera side of the aisle, and mean that EOS Movie is a valid and viable alternative for many serious video professionals in certain conditions.
And for the serious still photographer, there’s no denying the influence and power of multi-media in our lives. Fueled by the internet, many viewers of imagery, even casual viewers, expect to be enlivened with sound and motion, and video is the tool to deliver this. With the EOS 7D, you have two tools in one — a splendid high-performance digital SLR one moment, and a superior-performance video camera the next. |