Blackmagic Design Pocket Cinema Camera Manuel D'installation Et D'utilisation page 184

Choosing Frame Rates
Your camera is able to shoot video using many different frame rates and you may be
wondering which is the best one to use.
Generally, when selecting a sensor frame rate, there are some common items to
consider. For many years, there have been presentation standards for film and
television. These have set frame rates that differ between countries, but all share the
same purpose; to display an efficient number of frames every second that portrays
pleasing and convincing motion.
Cinema, for example, uses a standard 24 frames per second and while there have been
recent experiments with faster frame rates, 24 frames per second remains widely
accepted for international audiences.
Television frame rates have generally conformed to technical broadcast standards for
each country. For example, if you were making television content you would typically
record using 29.97 frames per second for North American distribution, and 25 frames
per second for Europe.
However, as technology has improved, today we have more choices and broadcast
standards are changing. It is now common for sporting events to be recorded and
broadcasted at higher frame rates. For example, some sporting events are recorded
and broadcasted at up to 59.94 frames per second in North America, and 50 frames
per second in Europe. This provides smoother motion on fast action and appears
more lifelike.
Alternatively, streaming and online broadcasters normally use frame rates similar to
television, however there is more freedom to experiment due to user selectable
viewing formats, and being limited only to what the audience's screens are capable
of displaying.
Generally, when choosing a frame rate for a project, let your delivery format guide your
choice. Your camera's project frame rate should be set to this, and your sensor frame
should be set to 'match'. This means your clips will play back at the same speed the
event happened in real life.
If you are looking to create an interesting effect, for example slow motion, then you can
set the sensor frame rate to a higher setting. The higher the sensor frame rate
compared to the project frame rate, the slower the playback speed.
For more information on using off speed sensor frame rates to achieve creative effects,
refer to the 'touchscreen controls' section.
Trigger Record
Blackmagic Pocket Cinema Camera automatically sends a signal via the HDMI output that will
trigger recording when connected to equipment that supports the trigger record feature, such
as Blackmagic Video Assist.
This means that when you press record on your camera, your external recorder also starts
recording and stops when you stop recording on the camera. Your camera also outputs
timecode via HDMI, which means the clips recorded on your external recorder has the same
timecode as the clips recorded in your camera.
If your external recorder supports trigger recording, you will need to enable it. This can usually
be enabled via its settings menu.
Recording 28