|
Preset Balances
(Return
to Camera Form)
The Preset Balances are the settings at the Preset, or 3200
mark, on your camera. We are checking 100IRE/100% White Balances,
Gamma Balances and 0, 9, 18 db Black
Balances. We use the Sony PTB 500 Pattern Box
which has a color temperature of 3200 degrees
Kelvin, plus or minus 20 degrees. We look for color shifts in all
the above mentioned areas. We will note on the form if your Preset Balances
are tinted blue, red or green. Please note that many current broadcast cameras
base their Auto White/Auto Black Balances on the Preset White and Black Balances.
If these are not balanced correctly, your Auto White/ Black Balances may
not be correct every time.
Gamma Setting
(Return to Camera Form)
Gamma is the correction made to the camera signal to balance the non linear
response of a picture tube (CRT). So, we make the camera non linear to correct
for the picture tube! A monitor/T.V. picture tube (CRT) is slow to respond
from dark to light image. We correct the camera in the opposite direction,
by making it seem to respond too fast from dark to light. The result is a
normal looking picture. The number we have checked off on your Evaluation
Form relates to how linear your Gamma is set. This number is known as the
Gamma Cross Over. Note that there is no specified factory value for this
number. Some cameras are set at 63IRE, others at 60IRE, and even others at
58IRE. The lower the IRE value, the darker the black areas are, while the
higher the number, the lighter they are. Any value between 50IRE to 65IRE
is valid. Ask your camera technician or fellow camera operators for more
information on how this affects the overall look of your camera, and how
to set it.
Knee Point Setting
(Return to Camera Form)
The Knee Point is the starting point for White Compression. This setting
helps retain more detail in your picture above the specified Knee Point,
which is normally somewhere around 100IRE or the 100% point. A normal "broadcast"
setting is 98IRE. This starts White Compression just before the camera reaches
100%. There is no actual standard for this setting. Depending on where your
White Clip is set, you may have a Knee Point of anywhere between 90IRE/90%
and 105IRE/105%. You may contact your camera technician to find out how to
change this setting. This is also a setting that can change the look of your
camera.
The Linear Matrix
(Return to Camera Form)
(Please note that not all cameras have a Matrix installed
in them. The Matrix can be found in most of the High End Professional Cameras
and in ALL the Broadcast Cameras.) Have you heard of the Matrix or
Masking in your camera? They are really one and the same. In many cameras
it is known as a Linear Matrix. This means that it's effect on the picture
is in a linear fashion, not a sudden change. What this does for you the user
is allow you to change the hue of your color. You can have a little more
blue looking green or more yellow looking reds, either one is possible. This
can all be done without having an effect on the white balance of the camera.
On most all cameras the Matrix/Masking is switchable. With the switch off,
you have the factory look of the camera. With the Matrix on, and with
the help of your camera technician, you are able to adjust the colors to
your liking. Many different color charts are available for this type of set
up. DSC of Canada makes a SMPTE color chart. You can also use the McBeth
color chart. Or you can actually select various colors of red, blue, green,
yellow, magenta and cyan and use those. From there the Matrix is adjusted
for the color look you want. If you mark the spots on the vector scope after
you are done with the alignment, you can adjust another camera to the same
points. Use a piece of plastic that you can save for the markings. You can
also match, to some extent, two different manufacturer's cameras using the
Masking/Matrix in your cameras. This is a large part of making your own custom
look for your camera. Have your camera engineer show you more about the
Masking/Matrix in your camera
Encoder Color Bar Check
(Return to Camera Form)
This is to check the performance of your NTSC Encoder in your camera. We
check for the level of Color Bars, Setup Level, and White Levels. We will
note if any of the levels are high, or need adjustment. It is recommended
that you have any adjustments made soon, if anything is out of specification.
Please remember that the color bar generator in your camera is only a
reference for
you, not a
reference standard color bar generator.
Detail
(Return to Camera Form)
Detail is a subjective setting. We only note the percentage of detail we
find in your camera. Detail settings can be from 0% to 20%. Normal factory
detail is set at 5%, when the camera is shipped. Your camera technician can
help you adjust this to a look you find pleasing.
White Clip
(Return to Camera Form)
The form you receive is marked based on the settings in your camera as we
receive it. The White Clip is the actual peak of the picture where we stop,
or clip the video information. 100 IRE represents a 100% picture. We can
allow for up to 10 IRE or 10% more picture if we are using a component recording
system, such as Betacam, or even 15 IRE or 15% more with some other recording
formats. However, there is no actual standard for the White Clip setting.
All values from 90IRE to 115IRE are valid. This form simply shows you where
your camera's White Clip has been set.
Zebra Settings
(Return to Camera Form)
The Zebra setting is the stripes in the viewfinder that tell you how to expose
your picture. A normal "broadcast" setting is 75% which corresponds to flesh
tones. However, all values from 50% to 100% are fine. This is a setting of
personal preference that can be adjusted to each individual camera operator's
preference. You can have your Zebra set to your preference by a qualified
technician, or you can read about how to do it in the service literature
for your camera.
Customer Supplied Lens
(Return to Camera Form)
We note this section to tell you, the camera owner, how we checked the
performance of your camera. If we supplied a lens, some of the information
regarding White & Gamma balances may not be correct. It is recommended
that any camera be set up or aligned with the lens that is normally used
attached. Different manufacturer's lenses have slightly different responses
to color. If a camera is aligned with one manufacturer's lens, and another
manufacturer's lens is attached, it may have a different response to color.
Notes
(Return to Camera Form)
Almost all camera settings are actually up to the user or owner of the camera.
Most all the settings we are checking are subjective and can be changed by
a Qualified Dealer Service Technician, or by the manufacturer's service center.
For more information on camera settings, please contact your local
Qualified Dealer Technician or your nearest Factory Service Center. |
|