Canon 70D Video

Canon 70D Video Recording

The EOS 70D is Canon's latest entry in the HD-DSLR market, and the company is aiming to make a big splash with it, thanks to its brand new Dual Pixel CMOS AF focusing system. When Canon introduced the 5D Mark II, it stunned crowds with its video quality and price, but it lacked a big mass-market feature: autofocus during video recording. Several more recent Canon DSLRs such as the T4i, T5i and SL1 feature full-time continuous AF for video recording, but they still rely heavily on slower and sometimes-jerky contrast-detect autofocus to fine-tune focus. With the 70D, Canon has introduced its all-new Dual Pixel CMOS AF, replacing the Hybrid AF systems found in the aforementioned models with one that splits each individual pixel on the imager into its own phase-detect AF sensor, with no need to fine-tune via contrast detection. Phase-detect AF, the same AF technology DSLRs use for shooting with the optical viewfinder, provides much faster and smoother autofocus for DSLR video shooting.

Canon is putting interchangeable lens video/still cameras like the Panasonic GH3 squarely in its sights. The GH2 and GH3 made big leaps in the HD-DSLR/MILC video space with lots of video-centric features like higher bitrates, an articulated LCD screen, as well as full-time AF for video. With the 70D, Canon is blending features of their higher-end DSLRs, such as offering both ALL-I and IPB formats and time code (though not SMTPE) from the 6D and 5D Mark III, with the articulated LCD of the 60D (adding a capacitive touchscreen in the process), all at a very reasonable price point. And this whole package is built upon a game-changing AF system that will not only provide major competition to other MILCs and HD-DSLRs, but some segments of the camcorder market as well.

Other video specs of the 70D are fairly standard fare for Canon DSLRs. Like the 60D, there's Full HD 1,920 x 1,080 resolution video at 30p and 24p (for NTSC, 25p in PAL mode), plus 720p HD video at 60p (50p PAL). There's also a 3.5mm microphone jack for external mics, as well as manual audio level adjustments with a wind filter and attenuator.

Of course there are always trade-offs, and there are few small details that might deter some users from the 70D. For one, there's no headphone jack for monitoring audio, which many professionals and video enthusiasts need. Also, video image quality appears more like the 5D Mark II and 6D in terms of moiré and aliasing. Canon users who demand the highest quality might opt for the 5D Mark III if this is a deal breaker for them, though they will have to forgo full-time autofocus.

All in all, though, the Canon 70D is a powerhouse for video recording, and not only will high-end users be attracted to the vastly improved autofocus, beginners and average consumers will as well. Here's the full rundown of the 70D's video capabilities, along with our usual selection of sample videos.

Canon 70D Video: Focusing

The clear stand-out feature of the 70D is the new Dual Pixel CMOS AF system. Canon's previous full-time continuous video autofocus systems, called Hybrid CMOS AF (T5i, T4i, EOS-M) and Hybrid CMOS AF II (SL1), used both phase-detect and contrast-detect AF. The way this system worked was that phase-detect would get the ball rolling for focusing, then contrast-detect would take over for fine-tuning to achieve crisp focus. The downside is that this process is typically slower, plus the lens still has to hunt back and forth a bit to determine the point of best focus. This can have undesirable effects for video recording, as focus can jump back a forth if the subject moves at all in the frame during recording, and if the subject moves quickly, the camera may struggle to refocus.

With the new Dual Pixel system in the 70D, Canon has designed an autofocus system that uses phase-detect AF all the time, both before and during video recording. What this means is that there's no more hunting when focusing, and AF is quite fast to acquire focus. Furthermore, Canon has designed the AF system for video to be very smooth and more "cinematic," shifting focus smoothly from one subject to the next. The autofocus on the 70D looks very much like a professional camcorder in terms of smoothness and performance.

As with the Canon SL1's Hybrid CMOS AF II system, the new Dual Pixel CMOS AF in the 70D system utilizes an extremely large area of the sensor for autofocusing, as shown in the illustration below. In fact, 64% of the total area of the sensor (80% of the frame, vertically and horizontally) can be used for phase-detect AF.

On the outside, the 70D functions similar to other Canon DSLRs with Movie Servo AF. Users are given three different focus options:

• Flexi-Zone - Single: Users are given a small, moveable AF area.
• Flexi-Zone - Multi: A larger AF zone, covering the full 64% sensor area, and the camera will automatically select and lock on to the subject closest to the camera.
• Face+Subject Tracking: The camera will find and lock on to faces automatically within the 64% boundary. Users can also manually select the subject for tracking by using the touch screen to tap on the subject they wish to track or by using the Set button and the directional keys.

The Canon 70D features a large, 3-inch capacitive touch screen which, when coupled with the Dual Pixel CMOS AF, allows for very fast and easy control of autofocusing in video. When using Movie Servo AF and the touchscreen and focusing modes like Flexi-Zone Single, shooters can make easy and professional-looking focus changes simply by tapping on the screen to indicate the subject they want in focus. The Touch AF system makes it easy to rack focus from near and far subjects quickly, accurately and smoothly, without any hunting.

Of course, manual focusing is also available on the 70D, as is disabling the continuous Movie Servo AF feature and using a single-shot autofocus prior to recording video to set focus. The 70D does provide the option of magnifying the Live View display by factors of 5x or 10x to get a precise look at manual focusing prior to the start of recording. In common with all other HD-DSLRs we've seen to date, though, the magnified focus-assist view is only available when not actively recording.

• Single autofocus operations can be triggered before or during movie recording by half-pressing the shutter button or pressing the AF-ON button.
• Depending on the lens in use, on-camera audio will likely pick up significant autofocus drive noise. This can be minimized by using an external microphone, however. Canon's new STM lenses are nearly silent, though, so an external mic would only be needed in very quiet surroundings with them.
• Face detection autofocus is available prior to recording, and continues to track face locations during capture.
• AF point can be positioned with the multi-directional button, or the touchscreen before or during recording, but cannot be placed at the extreme edges of the frame.
• Manual focus is also available during movie recording.

Competitive AF tracking test

We had a fair range of AF tracking examples from outdoor shooting, but wanted to try some more controlled indoor tests. We'd seen an example posted by someone on the Internet (sorry, can't recall who, to give them fair attribution), of a little stuffed animal swinging as a pendulum, showing how well the Canon 70D did, particularly with an STM lens. We decided to repeat that test, and use it to compare between three different cameras.

In the videos below, the subject was a small, stuffed dog toy, hanging from a length of monofilament fishing line about 3 feet long. It was positioned about 8 feet from the camera and about 30 inches in front of the background poster. The arc it traveled had a maximum extent of +/- 10 inches relative to the camera position. In all cases, the focal length was roughly equivalent to a 140mm lens on a 35mm full-frame camera. The amount of focus actuation required by the combination of focal length, distance, and subject movement is probably at the edge of what you'd encounter filming a real-world subject: The little swinging toy was moving quite a bit & fairly rapidly, relative to the long focal length and relatively close shooting distance.

The results were interesting. The 70D with the 18-135mm STM kit lens did indeed do pretty well, although we found that it tended to lag slightly, particularly as the subject changed directions. Importantly though, the operation of the focus-actuation motor was virtually inaudible. Trying the same test with a lens having a conventional focus motor (the Canon 24-105mm f/4L), we found that the AF didn't track quite as closely, and the focus motor's noise was very evident on the audio track.

In our outdoor AF tests with the Canon SL1 and its Hybrid-II AF system, the SL1 did quite well tracking larger moving objects, in many cases performing nearly as well as the 70D. It didn't do nearly as well in this lab test, though, as it rarely seemed to adjust focus at all, in response to the varying distance of the subject. It performed by far the poorest of the three cameras in this little comparison test. We used the 18-135mm STM lens for this test.

The third camera we tested with this setup was the Panasonic GH3, and we were rather surprised by how well it did, using Panasonic's 14-140mm f/3.5-5.6 lens. It didn't track perfectly, but then none of the cameras did with this setup, and the GH3 seemed to perform at least as well, if not slightly better than, the 70D. We were surprised, as the GH3 uses strictly contrast-detect AF, so the camera has no absolute distance information to work with. Nonetheless, perhaps thanks to its very fast 240 Hz AF cycle and intelligent tracking algorithms, it managed to track the rapidly moving subject surprisingly well.

Canon 70D Basic Video Specs

• 1,920 x 1,080 (Full HD / 1080p); 1,280 x 720 (720p); or 640 x 480 (VGA) recording
• MOV file format, with variable bitrate MPEG-4 AVC/H.264 encoding
• Choice of two compression types; ALL-I (intraframe) or IPB (interframe)
• Manual exposure mode possible in M mode; all other modes (P, A, S, B all revert to Program Exposure)
• Manual mode allows automatic or manual ISO control; sensitivity is controlled automatically in all other modes
• Exposure compensation and exposure lock are available
• Shutter speeds range from 1/4,000 down to 1/30 seconds (for 720p60/50, 1/60 sec. is slowest shutter speed)
• Sensitivity ranges from ISO 100 to ISO 12,800
• Features like color space, white balance, picture style, auto lighting optimizer, peripheral illumination correction, chromatic aberration correction, and highlight tone priority are all available for video
• If an external flash unit has an LED light, the 70D can automatically enable it in low-light shooting. When shooting with external flash in modes other than M, the LED will turn on automatically under low-light conditions.
• TTL (through the lens) evaluative or center-weighted average metering using the main image sensor
• Single autofocus with face detection and adjustable AF point, available before or during movie recording
• Continuous autofocus fully supported, with Face+Subject Tracking
• Manual focus is also available
• Dedicated live view toggle switch
• Video recording can be started and stopped with dedicated movie button or optional RC-6 remote control
• Seven-step LCD brightness adjustment available
• LCD brightness must be adjusted before capture starts
• If lens supports optical image stabilization, this operates at all times before and during capture unless switched off on the lens
• Optional 16-bit, 48KHz, 1,536 Kbps Linear PCM audio from internal stereo microphone or external 3.5mm stereo jack
• Automatic or 64-step manual audio level control
• VU (audio level) meter display before and during recording when manual control is enabled
• Pre-recording VU readout calibrated in standard dB units
• Optional wind cut filter function reduces levels for low-frequency audio
• Records time code, and can be set to continue to increment code regardless of capture status, or only while movie capture is underway
• Time code is recorded in hours, minutes, seconds, and frames, and can be reset, set to camera time, or set freely (Note: Not SMPTE format)
• Time code can be displayed on-screen during capture and playback
• Drop frame function will correct time code slip at 29.97 or 59.94 fps, but not at 23.967 fps or PAL frame rates of 25p/50p
• Cannot output uncompressed live feed via HDMI
• Movies can be "trimmed" in-camera, selecting just the portion you want and optionally saving it as a new file
• Video duration limited to 29 minutes, 59 seconds
• File size restricted to 4 GB maximum; new file is automatically created when the 4GB limit is reached and recording is not interrupted (but the resulting files won't automatically play sequentially; you'll need to manually play the second when the first is done)
• If sensor temperature threshold is exceeded, shooting may stop before either limit is reached; camera warns before threshold is reached
• Single SD memory card slot. Uses SD, SDHC, SDXC cards.
• Still images can be captured during video recording, but will interrupt the video feed for approximately one second and won't fire an external flash. When shooting in HD video resolutions, still images will be in 16:9 aspect ratio; 4:3 ratio when using SD resolution video.
• Continuous bursts of stills can also be shot, but they won't be reviewed on the monitor, and the video (obviously) pauses longer. An artificial "shutter sound" is recorded on the audio track to mark the point at which the still shots were taken.
• Histogram is available in manual mode, but only before capture starts
• Single-axis virtual horizon level is available in all exposure modes, but only before capture starts, and not if using face-detection autofocus or HDMI output
• Three grid displays (3x3, 6x4, and 3x3 plus diagonals) are available, but only before capture starts
• "Video snapshot" function, automatically strings together collections of 2, 4, or 8-second video clips to create a "highlights reel" with optional background music

Canon 70D Video: Image Size, Frame Rate, and Encoding

The Canon EOS 70D offers three different video resolutions and five frame rates, although only two or three rates are available at any given resolution.

The Canon 70D, like all of Canon's video-capable DSLRs, only shoot in progressive scan formats. Although television broadcast video works well with interlaced formats, progressive video is more suited for computer playback and avoids deinterlacing issues.

Canon's DIGIC 5+ image processor gives the 70D capability for both 1080p and 720p video recording. The 70D, along with all Canon video-capable DSLRs (with the exception of the $12,000 EOS 1D-C cinema DSLR and its siblings) still do not provide the option of full 1080p video at 60 frames per second, which could be a drawback for more professional shooters who need that combination.

The 70D limits the minimum shutter speed depending on the frame rate. For 30p/25p/24p, users are limited to 1/30th of a second. For 60p and 50p video, you are limited to 1/60th of a second.

The inclusion of 720p HD video at 50/60 frames per second is a great feature, as it allows users to more easily film fast action scenes. The faster frame rate also helps should you want to produce some slow-motion video in post-production. It might not be the best format to use in low-light scenarios, however, due to the slowest allowable shutter speed being 1/60th of a second at those frame rates.

The Canon 70D records all video using MPEG-4 AVC/H.264 encoding, at variable bit rates in the .MOV format. Like the 6D, the 70D gives features two compression schemes in the HD resolutions, ALL-I or IPB. The difference lies in how each frame of the video is compressed. Not surprisingly, there is no uncompressed "RAW" video capability in the 70D. ALL-I format, nevertheless, yields a higher image quality by compressing each frame individually, at the expense of file size, whereas IPB is an "interframe" scheme and compresses multiple frames at a time. This results in a slightly lower quality picture, but the files produced are roughly a third the size of those for ALL-I.

Most computers and editing programs made within the last few years should be able to play 70D files with little problem, but high-def files may strain older systems, especially during editing of IPB video. For users shooting video destined for video editing software, ALL-I format video is the format to pick if your memory card can handle the space and increased bit rate. File sizes for the 70D's ALL-I clips can be massive, as you can see in the MB/minute rates listed in the table above. If you can handle the storage requirements and require higher image quality, choose ALL-I. Canon recommends using at least 20MB/second or faster Secure Digital memory cards for ALL-I, and 6MB/second or faster for IPB. Even faster cards will be needed if you plan on shooting stills during video capture, which will cause a brief interruption to the video feed. If your card is not fast enough, a five-step buffer fill warning will appear on the LCD screen.

Canon 70D Video: Image Quality

The 70D produces very high image quality in video, with great, crisp detail and accurate color rendition. Scenes shot in bright daylight look a bit too contrasty to our eyes, though, with shadow areas being pretty dark with the Standard Picture Profile. Users looking to get the most dynamic range out of their clips should use a custom picture style with decreased contrast. In low-light scenes, the 70D did a great job, with nice detail overall and decent shadow detail. While there was visible high ISO noise in our nighttime test videos, it wasn't severe enough to significantly degrade the image quality.

Although we saw much-improved handling of moiré and aliasing effects in the 5D Mark III compared to its predecessor, that doesn't seem to be the case with the 70D. In our test videos, a fair number of moiré pattern artifacts could be seen in the standard problem areas like window screens, roof shingles, and fine patterned fabrics. Moiré and aliasing are even more pronounced in 720p video, which has been the case with other Canon DSLRs we've seen in the past. Overall, moiré artifacts look very similar to those seen on the 6D and 5D Mark II. This isn't a deal breaker by any means, and while it could be a deciding factor for professionals or high-end video shooters, most users should just be careful where they shoot and be on the lookout for problems with the patterns in people's clothing, etc.

Below you can see our standard array of sample videos for the 70D:

Canon 70D Video: Exposure Control

Like most previous Canon DSLRs with video recording, the 70D allows for full manual exposure settings and adjustments including full control of shutter speed, aperture and ISO before and during recording. In all modes, except for M, the 70D switches to automatic exposure adjustments while in live view movie mode. As such, the 70D is very user friendly for both kinds of shooters: those that want a simpler video shooting experience and more advanced users who want more control over how their videos look. (It still would be nice, though, to have options like aperture priority available.)

• Defaults to fully automatic Program exposure in all modes except for Manual mode
  • Aperture and shutter priority modes revert to auto-exposure when recording video. ISO, Shutter Speed and Aperture are set automatically.
• Manual mode gives access to both shutter speed and aperture, and allows automatic or manual ISO control
• Exposure compensation adjustment is available with a +/-3EV range in 1/3 EV steps in Program or priority modes, but not in A+ mode
• Exposure can be locked with the * button and canceled with the AF point button, except in A+ mode. This also applies in Manual mode if shooting with Auto ISO sensitivity.
• Adjustments to all exposure variables can be made either before or during recording, but they are applied immediately, so the effect is not subtle. Aperture mechanism noise will vary depending on the attached lens.
• Available shutter speeds range from 1/4,000s down to 1/60s for 60p or 50p, and 1/30s for 30p, 25p or 24p
• Apertures depend upon the lens in use
• Sensitivity varies from ISO 100 to ISO 12,800
• Highlight Tone Priority is available, but disables the ISO 100 setting; defaults to ISO 200. Highlight Tone Priority also limits maximum ISO to 6,400.
• Color space, white balance, and Picture Style settings apply to movie recording. Picture Style types are Auto, Standard, Portrait, Landscape, Neutral, Faithful, Monochrome, and User Def 1-3, and each can be adjusted for sharpness and contrast, plus saturation and color tone for color styles, and filter / toning effects for monochrome.
• Picture Style, white balance, exposure, auto lighting optimizer, peripheral illumination and chromatic aberration correction, and highlight tone priority effects are all previewed on LCD monitor
• If an attached Canon flash unit has an LED light, the 70D can automatically enable it in low-light shooting in all except Manual mode

Canon 70D Video: Audio Recording

The Canon 70D has similar audio recording features to the 5D Mark III. Like many previous Canon video DSLRs, the 70D gives users the choice of recording audio with an internal stereo microphone or a third-party external stereo microphone via a 3.5mm mic jack. Audio levels are fully adjustable, with wind-cut filter and attenuator options.

The big downside to the 70D's audio capabilities is that, unlike the 5D Mark III, the 70D does not feature a headphone jack for monitoring audio. This was a much-lauded feature when it was finally introduced into the Canon DSLR lineup with the 5D Mark III. Many advanced video shooters will surely be a little disappointed to find this feature missing.

• Audio is recorded as 16-bit, 48KHz, 1,536 Kbps Linear PCM
• Internal stereo microphone
• Defaults to automatic level control (aka Automatic Gain Control)
• Manual level control available via Shooting Menu item, with 64 levels available. Left/right balance is not adjustable
• VU (audio level) meter display is displayed on the same menu screen, and includes peak hold indication
• Pre-recording VU readout is calibrated in standard dB units
• VU meter display is also available as an overlay during recording by pressing the Info button
• VU meter only available if using manual audio levels
• External 3.5mm stereo mic input. Use external mics for better sound quality, control over stereo effect / directionality, and to eliminate camera / lens noise.
• Audio can be turned off entirely
• Optional wind cut filter function reduces levels for low-frequency audio
• In A+ shooting mode, audio levels are controlled automatically, and the wind cut filter is always active

Canon 70D Video: Rolling Shutter Artifacts ("Jello effect")

Like all video-capable DSLRs and interchangeable lens cameras on the market today, the Canon 70D has to contend with rolling shutter artifacts. These image distortions are caused by the way the image is read from the camera's sensor. Data is read line-by-line, rather than the entire frame at once, so the top of the image is recorded at a slightly different time than the bottom. Therefore, when panning or moving the camera side-to-side quickly, vertical lines in the image can appear to bend and slant back and forth in a "Jello-like" effect.

The 70D did pretty well controlling the amount of rolling shutter distortion. At the 1080p resolution, rolling shutter distortion was noticeable but minimal, and even less so at 720p. Overall, the 70D places well within the upper range of DSLRs when it comes to rolling shutter. As long as you are mindful of this effect, and avoid quick pans or back-and-forth motions, particularly around objects with vertical lines like trees and buildings, you probably won't notice the rolling shutter distortion.