Recording Resolution - ARRI ALEXA Mini LF User Manual

Recording
16.3

Recording Resolution

Recording Resolution Naming Scheme
Recording Codec
The Recording Codec defines the image content encoding. The options are ARRIRAW or
Apple ProRes.
Sensor Mode
The sensor mode defines the size of the area on the sensor that is read out. This influences the
maximum possible frame rate, the maximum data rate and what lenses can be used, as some lenses
may not cover a large sensor area. The Sensor Mode part of the name is further divided into three
parts:
First is the number of horizontal photosites used on the sensor in "K" (thousands).
Second is Large Format "LF" or Super 35 "S35", provided so a quick choice can be made without
memorizing resolution numbers. "LF" in this context is any sensor mode with an area larger than the
ALEXA Mini sensor in Open Gate, and "S35" is any sensor mode with an area equal to or smaller
than the ALEXA Mini sensor in Open Gate.
Third is the aspect ratio of the area on the sensor that is being read out.
Recording File Container Size
Recording File Container Size shows the resolution of the file that is being recorded in camera.
Sometimes, as in ARRIRAW 3.4K S35 3:2 - 3.4K, the number of photosites read from the sensor and
the number of pixels recorded are the same (here 3.4K), so no in-camera processing has been applied.
In other cases, as for instance in Apple ProRes 3.8K LF 16:9 - 2K the number of photosites read out
from the sensor is larger than the number of pixels recorded into the file. In this case, the in-camera
processing has downsampled the 3.4K image from the sensor to a 2K image recorded to reduce the
data rate. The aspect ratio of the recorded file is the same as that of the sensor mode and is therefore
not noted again.
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