Camera Settings
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 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.
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.
(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
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 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.
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.
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.
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.
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. | ||