More and more stills photographers are shooting video, or are being asked to add videography to their repertoire. The good news is: if you're using pro-level Canon cameras, you already have a world-class video production system in your hands. But having the equipment is just the beginning – there's a whole vocabulary of specific videography terms to get to grips with.
That's where this handy glossary of specialist video terms comes in. From codecs to T-stops, from Cinema RAW Light to Wide DR, our guide will explain 27 key terms and concepts that you never encounter in stills photography, or have a different meaning or specific application in the world of video. We'll take the confusion out of filmmaking and help you master the art of videography.
A 4K image is one with approximately 4,000 pixels horizontally. It's said to be the new standard, but the catch is that there's more than one variety of 4K. 4K UHD (Ultra High Definition) has a resolution of 3,840 x 2,160, which is the same 16:9 aspect ratio as HDTV. It is the most common type of 4K. 4K DCI, sometimes called Cinema 4K, is a 17:9 format with a resolution of 4,096 x 2,160. It is most commonly found on professional cinema cameras, such as the Canon EOS C500 Mark II, EOS C300 Mark III and EOS C200. By comparison, 2K is a 17:9 format at 2,048 x 1,080, while 8K is 16:9 at 8,192 x 4,320, which is double 4K DCI in each dimension.
With the arrival of the Canon EOS R5, it's now possible to capture footage in 8K. However, 8K input doesn't necessarily mean exclusively 8K output, and the EOS R5's 8K video capabilities bring a number of benefits to a 4K workflow. This includes the option of cropping a 4K image from the 8K frame at the editing stage, and 8K footage also makes it possible to use software to zoom, pan and stabilise after filming. As well as this, the EOS R5 features a 4K HQ mode that oversamples the video from 8K to give a 4K image that's more detailed when compared with footage shot natively at 4K.
A classic cinematography format where a standard-sized film or sensor capture is intentionally distorted to create a widescreen image. This is made possible using an anamorphic lens on the camera and de-squeezed horizontally at usually 2x or 1.3x to correct the image. Classic anamorphic characteristics include oval-shaped bokeh and long, horizontal flares.
Literally, the number of bits of digital data allocated to storing a pixel's tonal or colour information. The more bits, the more possible levels of colour or tonal gradation recorded. Some cameras record in 8-bit, which offers 256 possible shades for each colour channel. 10-bit files have 1,024 shades per channel, while 12-bit offers 4,096 shades per channel. The Canon EOS C500 Mark II can record 4K in 12-bit Cinema RAW, for example. Higher bit depth in principle means more tonal detail is recorded, allowing for smoother image gradients and finer adjustments when editing. However, higher bit depth increases file sizes.
Stills photographers often shoot RAW for maximum post-processing latitude, but RAW video files are so huge as to be unwieldy. The solution is to record using a logarithmic gamma curve such as Canon Log. This finely increases the details captured in the shadows while retaining information in the highlights. Canon Log expands the dynamic range of the image but also requires colour grading or a lookup table (LUT) to restore natural brightness and colour.
Currently, there are three Canon Log gamma curves, each of which offers a different degree of dynamic range expansion. On the Canon EOS C200, the original Canon Log and the latest Canon Log 3 can be applied in-camera. Canon Log 3 offers the most convenient blend of latitude and grading ease, offering a similar shadow response to the original Canon Log but with 13 stops of dynamic range. Canon Log 2 offers maximum dynamic range in excess of 16 stops on the Canon EOS C300 Mark III and EOS C70 with Dual Gain Output (DGO) sensors.
RAW video files offer productions maximum flexibility to manipulate the image in post, but the data rates of RAW are considerably higher than standard compressed formats. Canon's Cinema RAW Light format alleviates this problem, delivering a significant reduction in file size without sacrificing image quality. It is used on the EOS C500 Mark II, EOS C300 Mark III and EOS C200, and provides the highest possible image quality in a file that's approximately a third to a fifth of the size of a standard Cinema RAW file.
Designed especially for recording Full HD and 4K video for the broadcast and cinema industries, CFast™ 2.0 memory cards boast very fast read and write speeds to make post-production workflow more efficient and in-camera capture as fast as possible. Similar in size to a CF card but requiring a specific card reader, the small, reliable cards are also ideal for extreme conditions, working well in very high and low temperatures. Many Canon cameras use CFast™ 2.0 technology, from the EOS C700 FF to the compact Canon XC15 camcorder.
A codec is a software layer for encoding and decoding video files at recording and playback. Popular recording formats include XF-AVC, HEVC/H.265, MJPEG, MPEG-4 AVC/H.264 and AVCHD. Some codecs, such as the XF-AVC used in the Canon EOS C300 Mark III, provide outstanding image quality with a reasonable file size. Others, such as High Efficiency Video Codec HEVC/H.265, provide even more efficient data compression.
When editing video, the first step in getting colours right is colour correcting, which makes sure footage looks exactly the way the human eye sees things. Colour grading is the next step, where the aesthetic of the film is altered to convey a visual tone or mood. When a production has been shot using a logarithmic curve such as Canon Log, colour grading is an essential part of the workflow. Otherwise it may be an optional process, and commonly used to give videos a cooler, more cinematic look. Documentaries sometimes aren't graded if they aim for a rough-cut, "fly-on-the-wall" look.
The EOS C300 Mark III uses a new DGO (Dual Gain Output) Super 35mm sensor, which reads each pixel with two different amplification levels, one high and one low, which are then combined to make a single image. The higher amplification read-out is optimised to capture clean details in darker areas, while the lower amplification read-out is optimised to capture the details in brighter areas. When the two are combined, the details in the shadows and highlights are maintained and enhanced, which enables the camera to achieve an impressive higher dynamic range of up to 16+ stops.
A sensor-based autofocus system designed to provide fast autofocus acquisition and smooth, high-performance focus tracking in movies. It is built into all Canon Cinema EOS cameras and is compatible with more than 100 Canon EF and EF-S lenses. The Canon-developed technology is ideal for helping you achieve pull-focus effects and keeping a subject moving towards the user in sharp focus while maintaining a blurred background. A phase-detection system, Dual Pixel CMOS AF is generally faster than contrast-detection autofocus, which uses light sensors behind the lens to measure when contrast is at its greatest point, which corresponds to maximum sharpness.
Even when using manual focus lenses, or AF lenses in manual mode, cameras equipped with Dual Pixel CMOS AF technology can give a visual confirmation when a subject is in focus. This technology, which works with EF and RF mount lenses, was first seen on Canon Cinema EOS cameras and displays a symbol in the viewfinder that indicates which way the lens focus ring needs to be turned to achieve accurate focus.
With incredibly high data needs, video often benefits from the use of an external video recorder – a separate device that can display and record the video stream. Most cameras that can send a clean video signal out of their HDMI port (or SDI Out connection, where available) for recording do so without compression, making the footage captured in the external recorder higher quality than that saved in-camera.
Some advanced cameras, such as the Canon EOS C300 Mark III, EOS C200 and EOS R5, have the ability to recognise a human face – or multiple faces – and set those as the points for focus. When there are a number of people in the picture, one person will be determined to be the main subject, but you have the option to select someone else. The camera will keep tracking the main subject even when it moves. Additional options are available in the Face AF submenu, where you can choose between Face Only and Face Priority. Face Only will limit the AF strictly to what is recognised as a human face. Alternatively with Face Priority, should your subject leave the frame or not be recognised, the camera will revert to AF Frame so autofocus is still possible.
The EOS C70 features Canon's EOS iTR AF X, an advanced tracking and recognition system driven by "deep-learning" artificial intelligence. It’s clever enough to detect not just human faces but human heads as well, making it possible to maintain focus even when the subject turns and moves away from the camera.
This is a visual aid in the viewfinder or monitor to show which parts of your image are in sharp focus. In theory, areas in focus will coincide with the peak contrast, so the image is evaluated for contrast and these areas are highlighted on the display in a bright colour. You can see the highlighted areas of the scene change as you change the focus. Canon Cinema EOS Cameras have the feature, as do the Canon EOS R5, EOS R6, EOS R and EOS RP (the only non-cinema cameras to have this).
This is the frequency at which video frames are captured, expressed in frames per second (fps). Typical frame rates are 24fps for cinema, 25 or 30fps for broadcast video in different parts of the world, and 50 or 60fps for television in different parts of the world (25/50fps is for PAL regions while 30/60fps is NTSC regions). When edited on a 25 or 30p timeline, footage shot at 50/60fps can be slowed down to half-speed slow-motion. Higher frame rates such as 120 or 180fps are available on some cameras and can be slowed down for super slow-motion. The Canon EOS C300 Mark III and EOS C70 can film at 120fps in 4K with no crop of the image.
While most photographers think in terms of ISO, and some cinema cameras give you the option to use ISO settings, some traditional filmmakers think in terms of gain. This refers to the relationship between the input signal and the output signal of any electronic system. Higher levels of gain amplify the signal, resulting in greater brightness and contrast. Lower levels of gain darken the image and reduce contrast. So gain adjustment affects the sensor's sensitivity to light, just like ISO. See also DGO.
The basic HD format, also called 720p, has a 16:9 aspect ratio at 1,280 x 720 pixel resolution. 1080p is known as Full HD, with 1,920 lines horizontal resolution and 1,080 lines vertical resolution, so also a 16:9 format. The p stands for progressive, which means the data is contained in each frame, as distinct from interlaced (i), in which the image data is split between two frames in alternating lines of image data. Interlaced video takes up less storage space than progressively captured video.
The High-Definition Multimedia Interface is the most common type of connection for transmitting HD video and digital audio between devices, such as from the camera to a recorder. A Canon EOS C300 Mark III has a full-size HDMI type A socket, for example. Some cameras, such as the Canon EOS R5, have the more compact micro-HDMI socket.
Most standard computer monitors and TV screens cannot reproduce the full range of brightness – from shadow to highlights – that a camera's sensor is capable of capturing. So, many cameras capture footage in standard dynamic range, as the final output will be viewed on a standard dynamic range monitor or TV compliant with the standard Rec.709 or BT.709 8-bit colour space. HDR screens have a wider range (10-bit or 12-bit) and can display the greater colour range captured by video cameras that offer HDR or Hybrid Log Gamma settings conforming to BT.2020. Cameras such as the Canon EOS C300 Mark III, EOS C500 Mark II and EOS C700 FF all offer HDR capture.
Canon now offers a couple of image stabilisation technologies. The first is a lens-based system that compensates for unwanted movement or "camera shake". In Canon lenses that use this system, this is achieved by analysing movement with gyro sensors, then shifting a movable optical element within the lens to compensate for the movement and correct the light path so that the image on the sensor remains stationary. You can tell that a Canon lens has Image Stabilizer technology by the initials IS in its name. The Canon EOS C500 Mark II , EOS C300 Mark III and EOS C70 incorporate Electronic Image Stabilization in the camera body, supporting 5-axis camera shake correction. Even when used with lenses with no electronic lens communication, Electronic IS is possible by manually inputting the focal length.
An LUT or Lookup Table is a mathematical formula that modifies the colour of an image or footage. LUTs can be used for both technical and creative purposes, including Log conversion. A popular use is as a really quick way to grade your footage once you’ve colour-corrected it, allowing you achieve a distinctive look. LUTs are available for download that create a wide range of cinematic looks in post production environments such as DaVinci Resolve, Final Cut Pro X and Adobe Premiere Pro CC. Some monitors also have LUT support, so while filming you can see what the final footage will look like after the LUT is applied.
On Cinema EOS cameras there are a number of Picture Profiles available. These stored configurations can include Canon Log 2 and 3, HDR and Wide DR, and they can also be customised by the user. On top of this, colour spaces such as BT.2020 or Cinema Gamut can be selected, and the image can also be fine-tuned with adjustments including contrast, sharpness, skin detail and noise reduction. Colour matrix can also be selected to enhance compatibility with footage from other cameras.
Stills photographers are used to controlling exposure by altering shutter speed, but traditional movie cameras had rotary shutters instead of curtain mechanisms, so exposure time was determined by shutter angle. If film is advanced at the standard 24 frames per second, a 180-degree (half-circular) shutter will expose each frame for half the time or 1/48 sec. This produces a naturalistic look. That's why the so-called 180-degree rule states that shutter speed should be set to double the frame rate. Altering the shutter angle doesn't just change the exposure, though, but the aesthetic look of the footage – the beach-head scene in Saving Private Ryan, to take a notable example, was shot with a narrow shutter angle to replicate vintage newsreel footage. So for a naturalistic look that doesn't jar, cinematographers stick to the 180-degree rule, setting a shutter speed of twice the camera's frame rate.
T-stops – or Transmission stops – are used on cinema lenses and are more accurate at determining exposure than f-stops. The T-stop is an f-stop corrected for the amount of light reflected or absorbed by the lens. The f-stop is a theoretical value, while the T-stop is an actual tested value.
While many stills photographers are used to histograms as a graphical representation of images' brightness, filmmakers more often use waveforms. Unlike a histogram, a waveform produces an abstract version of your image, and viewing the waveform from left to right mirrors viewing the image from left to right, making it easy to quickly reference the brightness of specific areas of your frame. Filmmakers also rely on vectorscopes, which display six colour targets aimed at getting the colours matched in your films.
Wide DR gamma setting allows the camera to capture a wider dynamic range than traditional BT.709-based standard gammas. It falls between BT.709 and the much flatter Log profiles. If you shoot Log, then your footage will need to be graded, but Wide DR records more dynamic range from the sensor that can be used without the need for grading. Canon's Cinema EOS cameras offer Wide DR.