Grass Valley LDK 7500 User Guide - Manual (Page 11)

Introduction FilmStream mode 1-3
Streaming modes
FilmStream mode
The FilmStream mode differs from the HD video mode in that it
captures all information in a scene and stores it digitally without
altering any parameters. By avoiding video processing in the raw RGB
data, the output signal is a true and faithful representation of the light
from the scene. Thus the FilmStream digital data signals are full-range
signals suitable for film post-production without any loss of information.
Capturing the light
The Viper uses three high-definition CCD sensors to register the light
from the lens. The signals from these sensors are converted to R, G, and
B data values using 12-bit A/D converters. Using logarithmic calculations
this data is then converted to 10-bit values and transferred to a recorder
using a dual HD-SDI link. Full resolution is maintained: true-progressive
1920 x 1080 pixels for every color. No color sub-sampling, no color
space conversions, no irreversible video manipulations, no further
quantizations, and no compression is carried out.
HDStream mode
The output mode can also be set to HDStream. This mode provides
signals similar to the FilmStream signals but in a 4:2:2 HD-SDI format.
These HDStream signals are subject to white balancing in the camera
but like FilmStream signals, they do not undergo any other video
processing. HDStream mode is ideal when storage capacity is limited
or for applications where lower resolution signals are sufficient, such
as background for keying.