Canon T3 Video Recording

High-definition video capture has become a must-have feature in this year's digital SLRs, with essentially all the major manufacturers now providing some form of video capture in their DSLRs, and Canon's Rebel T3 extends video capture right to the entry-level in its own lineup. Being positioned as an entry-level camera, the Canon T3 forgoes more advanced features such as Full HD recording, manual or priority-mode exposure control, and external microphone connectivity that are typically found on enthusiast or professional models. For its target market, though, these features are likely overkill.

A couple of other omissions may cause some potential customers to look further up Canon's model line. The T3 lacks continuous autofocus capability during video capture, something that's still relatively uncommon, but is an attractive feature for consumer videographers not accustomed to manually pulling focus. Perhaps more surprisingly, the Canon T3 lacks the ability to adjust video resolution at all. There's no standard definition VGA mode, something that's pretty commonplace across the board in competing models. Of course, if you're planning to shoot exclusively in HD, this will be of little importance, but if you'll occasionally need standard-def video, transcoding after capture will be your only option with the Canon T3.

Still, the addition of high-def video capture in Canon's entry-level camera is definitely welcome news, and we're sure many consumer videographers will be more than happy to live with its limited scope, in order to obtain HD capture in an affordable, entry-level model.

Canon T3 Basic Video Specs

• 720p (1,280 x 720) HD recording at 29.97 or 25 fps
• MPEG-4 / H.264 AVC compression, .MOV container
• Single-servo contrast detection autofocus is optionally available during recording, albeit with actuation noise levels depending on the lens used
• Phase detection or contrast detection AF are available before capture starts
• Manual focus also possible
• AF point position can be manually controlled
• Programmed-auto exposure (no shutter / aperture-priority or manual)
• Exposure compensation and lock are available both before and during recording
• Picture style selections provide creative options
• Monaural audio recording via built-in microphone
• Image stabilization during video capture, if offered by lens
  

Canon Rebel T3 Video: Image Size, Frame Rate, and Encoding

The Canon T3's new CMOS sensor records high definition, progressive-scan video at a maximum resolution of 1,280 x 720 pixels with a 16:9 aspect ratio -- what's sometimes referred to as 720p. Two frame rate options are available, either 29.97 or 25 frames/second, with these options matching common broadcast television formats for the NTSC and PAL TV standards respectively, thus removing the need to transcode to the intended output frame rate after capture. Surprisingly, the Canon T3 doesn't offer any reduced resolution standard definition shooting mode, and nor does it offer Full HD / 1,080p video capture.

Individual movie clips captured by the Canon Rebel T3 are limited to a maximum of 29 minutes, 59 seconds, thanks to European tax regulations, although as it turns out, the 4GB limit on video file sizes will in practice restrict you to shorter movie clips anyway . The Canon T3 records its movies as MOV files using variable bitrate MPEG-4 AVC / H.264 compression, which is much more conservative of memory card space than the Motion JPEG format used by some cameras, and avoids some of the severe image quality loss suffered by AVCHD cameras when faced with significant amounts of change in image content between frames. (AVCHD uses a subset of the H.264 standard, among other things mandating a limit in recording bandwidth, which translates into a lesser ability to convey rapidly-changing detail.) The choice of H.264 comes with the requirement of greater processing power, though -- not only from the camera when recording, but also when playing back or editing videos. The more sophisticated encoding used in the H.264 standard requires quite a bit of processor power to pull it apart and put it back together again, so frame-accurate editing of H.264 requires a fast processor and capable editing program.

Here's a list showing what to expect for file sizes with the Canon Rebel T3's video recording:

Canon T3: Video Options
H.264 Format (.MOV file container)
Resolution	Encoding	Frame Rate	Clip Length	File Size
1,280 x 720 (720p HD)	NTSC	30p (29.97 fps)	29 minutes, 59 seconds	~210-230 MB/min
	PAL	25p (25 fps)

Canon recommends using an SD card with at least a Class 6 rating to capture and playback movies.

Here are some examples of video from the Canon Rebel T3, showing typical results under daylight conditions.

Canon T3: Video Samples (shot with EF-S 18-55mm f/3.5-5.6 IS II kit lens)
1,280 x 720, 30fps View on Vimeo | Download Original (12.4 seconds, 46.7 MB)	1,280 x 720, 25fps View on Vimeo | Download Original (13.1 seconds, 46.3 MB)
1,280 x 720, 30fps View on Vimeo | Download Original (13.2 seconds, 45.3 MB)	1,280 x 720, 25fps View on Vimeo | Download Original (17.1 seconds, 65.4 MB)

Canon Rebel T3 Video-Mode Focusing

Unlike some other video-capable digital SLRs, the Canon Rebel T3 offers autofocusing during video recording -- but only in single servo mode. You can trigger either a phase-detect or contrast-detect AF cycle either before recording, or a contrast-detect AF cycle during recording, by half-pressing the shutter button. When focusing during video capture, depending on the lens and microphone in use, and the degree of focus adjustment required, AF noise is likely to be picked up on the audio track. (With the 18-55mm kit lens, and the T3's internal microphone, AF noise is picked up very clearly as a high-pitched whine.) You can also manually focus the lens during a recording, and the true manual operation of AF on Canon's lenses means you can do this more or less silently, simply by being careful about turning the focus ring. (Some interchangeable-lens cameras we've tested use "fly by wire" focusing, whereby the focus ring only instructs the camera to move the lens elements rather than moving them directly via a mechanical coupling, which can mean that small clicks can be heard on the audio track every time the focus setting is changed, regardless of how slowly you turn the focus ring. With true manual operation of its lenses, the Canon Rebel T3 doesn't have this problem, although it's possible that a third-party or older Canon lenses might produce audible noise while their focus was adjusted.)

As we've noted in other SLR reviews, the good news with focusing for video is that you can get surprisingly good depth of field in video mode if the lens is stopped down, thanks to the relatively low resolution of the video image. With a pixel resolution of only 0.9 megapixels in the Canon Rebel T3's 720p HD video mode, images that would be unacceptably blurred as 12 megapixel still shots look perfectly fine as video frames. This not only provides greater depth of field at any given aperture, but is also more forgiving of diffraction limiting at very small lens apertures. Diffraction at small apertures means you'd usually want to avoid f/16 or f/22 for still images, but again, the results generally look perfectly fine at video resolutions. Unfortunately you can't manually specify the aperture, but assuming you're shooting under fairly bright conditions, the Rebel T3 tends to default to fairly small apertures by default, so you may be surprised by how little focus adjustment is needed during daytime video recording.

Canon Rebel T3 Video Exposure Control

Many video-capable SLRs these days offer either aperture-priority, shutter-priority, or manual exposure in their movie modes, but the Canon Rebel T3 limits you to solely automatic exposure. This means that the camera adjusts the shutter speed, aperture, and ISO sensitivity as needed for a correct exposure, keeping things simple, but prevents you from biasing the camera towards a wide aperture for shallow depth of field effects in bright lighting conditions, and from trading off noise levels to gain more depth of field in low light. On the positive side, a reasonably generous 3.0EV of exposure compensation is available in 1/3 or 1/2 EV steps, to ensure exposure is as intended, and you can use the T3's autoexposure lock function to prevent exposure levels changing as you pan across a scene with varying ambient light levels.

Canon Rebel T3 Video: Audio recording

Like most competing SLRs with video recording capability, the Canon T3 sports an internal monaural microphone that can record an audio track. Canon doesn't publish specs for the T3's audio recording capability, though video players report monaural 16-bit PCM audio at 48 kHz. Subjectively, audio recorded with the camera's internal mic seemed clear, although we don't currently test frequency response or sensitivity, and wasn't particularly directional, picking up noise from behind the camera as well as in front. While we noticed some audible hiss in audio tracks recorded with the in-camera mic in quiet environments, it didn't seem as significant as in some cameras we've tested, and fortunately, we didn't hear any audible "breathing" from the auto-gain system adjusting sensitivity as sound levels got louder or softer.

Internal mics are somewhat problematic, though, in that they're prone to picking up noise produced by autofocus operation, control actuation, or even just moving your hands while recording, and unfortunately the T3 lacks any provision for an external microphone with which to reduce the degree to which video clips capture these untoward noises. While we haven't noticed pronounced differences in how much camera-handling noise various models' internal mics pick up, they do vary significantly in terms of how much noise there is during autofocus operation, and with the kit lens, the Rebel T3's autofocus motor noise is extremely clear indeed. Of course, if AF noise is an issue, you can disable autofocusing during video capture to prevent accidental operation, or use a dedicated audio recorder and replace the audio track in post-processing. The Rebel T3 also allows audio recording to be disabled entirely through an option in Movie Menu 2.

As you'd expect from an entry-level model, the Canon T3 doesn't have any provision for manual audio level control. This isn't a particular strike against the T3, though, as manual level control is a feature found on only a few digital SLRs, and those are well above the T3's price range. To sidestep this limitation, many amateur videographers simply use a separate, inexpensive digital audio recorder to record a separate soundtrack, which they then synchronize with the audio from the camera in their editing software. Software synchronization of audio tracks gives essentially perfect alignment of the video and externally-recorded video with relatively little effort.

Canon Rebel T3 Movie Recording User Interface

The Canon Rebel T3's video mode is accessed via a dedicated position on the camera's mode dial. A dedicated Live View / Movie button to the right of the LCD panel is used to start and stop recording when the Mode dial is in the Movie position, and acts as a Live View button in other modes. Setting adjustments in movie mode are made via three dedicated Movie menus, which are only available when the camera is in Movie mode, although some items are shared with the Live View menu in other modes. Optionally, half-pressing the Shutter button can be configured to trigger a single autofocus cycle during movie capture. Pressing the shutter button also shows exposure variables, so if you have enabled autofocusing during video capture but want to check these variables, an option in the Movie menu allows autofocusing to be temporarily disabled by holding the the * button.

In Playback mode, the Canon T3 allows you edit out or trim the first and/or last scenes of a movie, in one second increments. You can save the trimmed movie to a new file (if there is space on the card), or choose to overwrite the original. Movies can be played back at normal speed, or in slow-motion, with adjustable playback frame rate. There are "VCR" like controls for advancing to the next or last frame, or playing from the previous or first frame.

Rolling Shutter Artifacts ("Jello Effect")

Canon T3: Rolling Shutter Artifacts (shot with EF-S 18-55mm f/3.5-5.6 IS II kit lens)
1,280 x 720, 30fps View on Vimeo | Download Original (6.6 seconds, 24.1 MB)	1,280 x 720, 25fps View on Vimeo | Download Original (5.7 seconds, 20.1 MB)

Essentially every video capable digital SLR currently on the market exhibits motion-related distortions called rolling shutter artifacts. These are caused because the image data is captured and then read off the chip sequentially by rows, rather being captured all at once. In the case of the Canon T3, with its variable frame rate, this means that image data for the last row of a given frame is captured and read out anywhere from 1/25th to 1/30th second after the data for the top row was captured. The effect on moving objects is similar to that of a focal plane shutter in an SLR, but more pronounced, because the video frame is read out much more slowly than the slit of a focal plane shutter moves across the sensor.

For a camera that scans video frames vertically (as all do that we're aware of), rolling shutter artifacts will be most noticeable for subjects that are moving rapidly side to side, or when the camera itself is being panned horizontally. Verticals in the scene will appear tilted to the right or left, depending on the direction of camera motion. As an example, consider the case of a camera being panned from left to right, with a flagpole or other vertical object in the middle of the scene when recording for a particular frame begins: If the top of the object was centered horizontally when the first line of the video frame is acquired, by the time the last line of the frame has been captured, the bottom of the object will have shifted to somewhere left of center: As a result, the vertical object would appear to be leaning to the right.

Computer Requirements for Viewing HD Video

A typical computer these days has little trouble dealing with still images, but high-definition video can be another matter. Depending on the file format involved, it can take a pretty beefy computer to handle HD-resolution video playback without stuttering or dropping frames. The AVC / H.264 image compression used by the Canon Rebel T3 is one of the more compute-intensive formats, but its fixed 1,280 x 720 pixel (720p) resolution means there's less data in each frame to deal with than with cameras offering Full HD capture. The net result is that most reasonably recent computers should play the T3's high-def video files just fine, but you will need a relatively powerful machine for video editing.

You can of course view your movies on a high definition TV via the HDMI output. If you're still on a standard-def TV, though, you're out of luck, as the T3 doesn't offer any form of standard-def video output connectivity.