With most cameras now capable of recording 4K video, we provide some advice on settings, focus, shooting, resolution, and camera capabilities.
If you haven’t yet explored the video capabilities of your camera, this might be a good time to start, particularly if your camera is relatively new. These days, just about every camera supports 4K video recording. Some of the latest models even include full professional recording capabilities and many of them are being used to record movies and TV programs.
In short, shooting video has never been easier and output quality can be superb. You can also do a lot more with 4K footage than you could with the lower-resolution formats.
In this feature, we’ll outline the cameras and settings you should use to ensure your clips are correctly exposed, sharp and shake-free.
Many of the latest mirrorless cameras, like the Nikon Z6 above, can be accessorised to enable professional video recording. (Source: Nikon.)
What type of camera to use
There are plenty of devices capable of recording 4K footage, ranging from still cameras and camcorders through to smart devices. Your choice will, at least to some degree, depend on what’s available, how straightforward and versatile it is and how important the quality and usability of the footage must be.
Camcorders are the easiest to use because they’re designed for recording video – ergonomically and with respect to the functions they offer. ‘Hybrid’ still cameras come next, with different levels of functionality and output options creating differences between particular models.
Shooting video with a smartphone makes sense in many situations, particularly as this type of camera is usually the most readily available. But while smartphones are convenient to use, they have some significant limitations.
- Smartphone sensors are tiny, with limited light-capturing capabilities compared with those in cameras with larger sensors.
- Their lenses are small, with a fixed focal length and relatively small maximum aperture, which also limits the amount light they transmit for exposures, leading to increased noise, which will degrade the picture.
- Only digital zooming is possible because there’s no space for a zoom lens. Although some of the latest smartphones include multiple lenses, zooming usually requires cropping the frame.
- Further cropping is required for digital stabilisation.
- The controls on smartphones are limited – even in the so-called ‘pro’ modes. Because the screen covers almost the entire surface of the device, they aren’t as easy to operate as camera controls. Relying on fully automatic shooting won’t necessarily deliver good results in all situations.
Even with the ‘pro’ mode, the controls offered by most smartphones are limited and having to use the touch-screen to make adjustments can make it difficult to frame shots while modifying exposure parameters.
If you’re already using a 4K-capable stills camera, its capabilities will probably exceed those of your smartphone and it will probably deliver better results. It’s worth noting that it’s generally easier to frame shots with mirrorless cameras that have electronic viewfinders (EVFs). Monitor screens can be difficult to use in bright outdoor lighting – which may prevent you from detecting potential flaws in exposure levels and focusing.
Sensor sizes and resolution
Most devices support the consumer-level 4K UHD format, which has the same 16:9 aspect ratio as most TV sets and a resolution of 3840 x 2160 pixels. However, some cameras provide the option to shoot ‘Cinema’ 4K, which uses the Digital Cinema Initiatives (DCI) resolution standard of 4096 x 2160 pixels. These models usually include professional functions like high (and/or variable) bit-rate recording, colour sub-sampling and video-orientated profiles. Check the camera’s manual to see what’s available and how these features can be used.
The differences in resolution between the two 4K formats and earlier video standards.
With the maximum resolution for a 4K video frame being around eight megapixels, photographers who are mainly interested in shooting video have no need for cameras with significantly higher resolution. Both Panasonic and Sony recognise this in their video-orientated ‘hybrid’ cameras: the Panasonic GH5S and Sony α7S II have sensor resolutions of 10.2 and 12.2 megapixels, respectively.
If you own a higher-resolution camera, the only disadvantage will be that the individual light-detecting photosites are smaller, the size differences being proportional to the differences in resolution and size between the camera’s sensor and the 4K format. Smaller photosites have greater potential for noise when shooting in low light levels, while more processing power is required to downsample higher-resolution frames to the 4K standards.
Bear in mind that larger sensors will usually provide more captured data than smaller ones, particularly if the video is downsampled from the full width of the sensor, rather than simply cropping out the central portion of the sensor’s full frame. However, they will also require more processing power to handle the data.
Accurate focusing is important and when capturing moving subjects, always use the continuous AF (AF-C) mode. (Some cameras set this by default whenever movies are recorded.) Autofocusing is often linked by default with exposure metering to make sure each frame is correctly exposed.
Continuous AF analyses the scene and focuses on a predicted point when the shutter button is half-pressed. If the subject moves, focus automatically re-adjusts while the shutter button remains half-pressed. The camera’s light meter will also determine the exposure in the selected focus area, while the shot is being framed.
Tracking AF will automatically follow a moving subject and keep it in focus, enabling photographers to re-frame without losing focus on the subject. The larger the area of the frame covered by AF sensor points, the easier it is to focus on and track moving subjects.
Roughly 80% of this frame is covered by AF sensor points – indicated by the white corner markings. The selected focus zone – shown with the green squares – can track moving subjects anywhere within the AF point array.
Make use of focusing and exposure aids like focus peaking and ‘zebra pattern’ displays. Focus peaking shows you what’s sharp by outlining in-focus areas in a contrasting colour (usually selectable from red, white, blue, yellow and black).
Focus peaking highlights areas in the scene that are in focus by superimposing outlines in a contrasting colour to the subject. Most cameras provide at least four colour options.
Zebra pattern displays overlay a series of stripes on areas in a scene that are too bright to be recorded properly. The pattern is not recorded in the video clip.
Most cameras let you set a threshold for the zebra patterns. Setting the threshold level to 100% means the patterns will only be displayed when parts of the image are already ‘burnt out’ because of the bright light. Adjusting the threshold to 80% will give you a 20% safety margin before problems arise.
Zebra pattern displays provide a quick way to identify potential blown-out highlights, which are indicated by flashing stripes overlaid on areas that are excessively bright.
Focus pulling is a popular shooting technique that involves moving smoothly from focusing on a subject near to the camera to a different one some distance away (or in the reverse direction). Some cameras enable the photographer to set the start and end points for a focus pull and control the speed of the change in focus via the touchscreen monitor (even when using the EVF to frame shots). Ideally, the camera should be mounted on a tripod to ensure smooth transitions.
Focus pulling creates a smooth transition in focus from a subject near to the camera to one at a distance – or vice versa.
Variable bit rate recording evaluates each frame and determines how much it can be compressed before its quality deteriorates. Some cameras let users define maximum, minimum and target bit-rates for encoding video files.
Bit depth and colour sub-sampling determine the density of colour information. Most consumer cameras stick with 8-bit depth (the same as JPEG images) but professional cameras often include 10-bit recording modes, which can reproduce 1024 levels per colour channel and are able to represent more than a billion discrete colours. An external recorder is often required to handle such a large data stream.
Still cameras commonly provide profiles for enhancing colour saturation (‘vivid’), adjusting colours to suit landscapes or portraits and monochrome conversion in addition to ‘standard’ and ‘neutral’ settings. These profiles can also be used for shooting movie clips but the end results can be difficult to edit.
Cameras that record video may add ‘flat’ or ‘log’ picture profiles with reduced contrast and saturation to produce clips that are suitable for post-production (editing). These profiles are designed to increase the dynamic range in the recording and provide tonal levels that are close to how our eyes perceive them, which means more realistic looking movies.
High bit-rate video clips deliver better quality but their files are large so they’ll require adequate storage capacity and fast data transfer times to minimise uploading or downloading times. An uncompressed 4K video stream at 25 frames/second (fps) has a typical bit-rate of approximately 12 Gigabits/second (Gbps).
Fast, high-capacity memory cards are required for 4K recording to ensure there are no glitches in the recorded sequences. The minimum requirement is an 8GB SDHC card with a Class 10 or higher speed rating. Look for cards with ‘V’ speed ratings (see more on memory cards here).
Time-lapse and interval recording modes
Many cameras permit time-lapse photography, a technique that records single frames at pre-determined intervals. Some provide an intervalometer where you set the exposure parameters for each frame and nominate the number of frames you want the camera to record over a given period of time.
When the sequence is played back at normal movie speed, it creates an impression of time passing quickly. Events that would normally take several minutes, hours or days can be viewed within a few seconds. Key requirements include a stable shooting platform, so the camera must be tripod mounted. You must also have enough battery power to complete the sequence and enough memory to store it.
This collection of shots is from a time-lapse sequence of 20 frames taken at 15-second intervals over a period of five minutes. Time-lapse is ideal for showing subtle changes in lighting and subject qualities.
There are plenty of suitable subjects for time-lapse photography, with the most popular being the night sky (star trails and moon movement), vehicle movements (day or night), people moving into, out of or through public spaces, creative sequences (cooking, creating art works), plants growing, flowers opening, bugs eating leaves, and rotting vegetation. Sunrises and sunsets are also good subjects, along with movements of clouds and shadows.
Article by Margaret Brown – see Margaret’s photography pocket guides