Hardware - Sony BVP-E10 Series Product Information Manual

10
10-1.

Hardware

Chapter 10 Glossary - Terms and Definitions
166
BVP-E10 Series Product Information Manual
The following are some technical terms that are
frequently used in camera brochures or technical
papers.
Adaptive detail
A technique used to eliminate unpleasant edges on
areas of the picture with strong contrast. A simple
limiter causes detail edges to become thick. Adaptive
DTL is a very effective function which reduces the
amplitude of the detail, rather than clipping it. It has the
further benefit of reducing aliasing
Adaptive highlight control
To improve picture highlight handling, the picture is
divided into several zones depending on the
brightness level. A knee circuit provides varying
amounts of knee compression; areas with little
information are compressed more, while those
containing more information have less compression.
In the case of Sony's HDC/BVP-Series cameras,
Adaptive Highlight Control is only applied to the video
levels higher than the knee point.
Aspect ratio conversion
Modern programme production can requires
origination in either 16:9 or 4:3 formats. Sony video
cameras for broadcasting and professional use
provide the aspect ratio conversion function in
combination with a digital filter. Some other
manufacturers perform this function by changing the
reading process of the CCD.
Auto knee/DCC
A device that automatically adjusts the knee point and
knee slope to increase the dynamic range depending
on the subject.
Black Gamma
Black Gamma is a function to change the Gamma
curve of dark portions of the picture.
Black shading correction
Black shading correction is used to compensate for
the irregular black shading which can be caused by
variations in the dark current of CCD elements and the
characteristics of power circuits.
Boost frequency
Horizontal detail correction is usually performed by
boosting the spatial frequency characteristics
between around 3 to 4 MHz. The peak of the frequency
boost can be adjusted in order to meet the users'
different tastes. A higher detail frequency results in a
finer, more film-like look.
CCD
CCD is the acronym for Charge Coupled Device. It is a
kind of semiconductor that converts an optical image
into electronic signals - the heart of a camera. After
accomplishing the conversion, each pixel (a kind of
photoelectric convertor) on the CCD first holds the
signal and then transfers it to the next cell, in a way
often described as a 'bucket brigade'. According to
the transfer method, there are three types of CCDs - IT
, FIT and FT CCD, although only two of these -IT and
FIT are used by Sony.
Colour bars
Almost all of the video cameras used for broadcasting
- have a colour bar generator. Although the colour bar
signal was originally developed for the adjustment of
an analogue encoder, it has become a standard
function for professional video camera. It can be used
to monitor the amplitudes of the luminance and
chrominance paths in the programme chain.
Crispening
Detail correction enhances picture sharpness but at
the same time also emphasizes the noise, which can
increase the picture noise. Crispening is a technique
that removes small amplitude DTL to improve the
signal to noise ratio. Crispening is also often referred
to as "noise coring".
Detail comb filter
The detail comb filter is used to reduce the diagonal
detail that interferes with the sub carrier to generate
cross colour in an encoded signal. However,
subjective resolution is reduced if the diagonal DETAIL
is reduced too much.
DTL mix ratio
Adjusts the mixture of detail correction before and after
gamma correction. Can be used to affect the relative
amount of detail in the light and dark areas of the
picture.
Electronic soft focus
The detail circuit can make the picture sharper, but it
can also soften the picture by inverting the polarity.
When used this way, Electronic Soft Focus is a function
to generate a gentle film-like picture. It is more
effective to improve the look of a presenter's skin
colour when used in combination with the Skin Tone
DTL.
Encoder
Inside the camera, video signals are processed as
independent Red Green and Blue component signals.
The encoder is a device used to convert the
component signals into composite signals such as
NTSC and PAL.
Flare correction
In an optical system, reflections and diffusion can
cause dark areas of the picture to appear lighter than
they should. Flare correction electronically
compensates for this phenomenon.
Gamma correction
A CRT has a non-linear relationship between screen
brightness and signal level. This non-linearity is known
as the Gamma Law of the CRT Logically; a TV set
should include compensation for the error because it is
part of a CRT's characteristics. However, in
consideration of the total cost, the industry has
reached an agreement with TV stations that the non-
linear correction should be carried out during
acquisition. This camera function is the Gamma
Correction. Although most broadcasters and TV
stations have their own internal standard for gamma,
this can vary significantly between them. As a result,
camera manufacturers need to include various gamma
settings to accommodate the different requirements.
Different gamma settings can also be used as a way of
creating a different 'look' to an image.
Gen lock
When using multiple cameras are used together in a
system, it is necessary to synchronize the horizontal,
vertical and subcarrier phases of the cameras. Gen
lock is a technique developed for this purpose to