Grass Valley LDK 7500 User Guide - Manual (Page 68)

1-4 HD video mode Viper
Technology
CCD sensor technology
The camera uses three 2/3-inch sensors that offer superior performance
and ultimate flexibility. The sensors have a high dynamic range and
high linear sensitivity across all camera lens apertures. These unique
9.2 Megapixel HD-DPM+ CCD sensors allow the camera to work in
several formats; 1080 lines at 24/25/30 frames per second or 720
lines at 24/25/30/50/60 frames per second.
This CCD sensor is based on the Frame-Transfer principle which is
best suited for progressive images. Frame Transfer technology also
ensures that there is neither lag nor smear. The Viper uses a
mechanical shutter which means that the CCD exposure has a similar
ramp to film cameras, thus providing similar motion characteristics.
Formats
The sensor consists of 1920 horizontal pixels and 4320 vertical sub-
pixels. By grouping the vertical sub-pixels, the vertical line count
can be set. Full resolution is preserved and the horizontal viewing
angle stays the same.
• 1080p
When four vertical sub-pixels are combined, the total line count
becomes 1080 lines. So, a 1920 x 1080 image sensor is obtained
with a 16:9 aspect ratio.
• 1080i
When eight vertical sub-pixels are combined, the total line count
becomes 540 lines. The second field is shifted four pixels to give
an interlaced picture.
• 720p
When six vertical sub-pixels are combined, then the total line count
becomes 720 lines. So, a 1920 x 720 image sensor is obtained with
a 16:9 aspect ratio. When set to 60 frames per second, slow motion
effects can be achieved during post-production at different playback
speeds.
• Cinemascope Aspect Ratio
When three vertical sub-pixels are combined, 1440 vertical lines
are obtained. By using the middle 1080 lines, a 2.37:1 aspect ratio