JAI AT-140GE - Manual (Page 35)

AT-140GE
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9.4.2 White balance
The AT-140GE has 4 white balance modes: manual balance, one push auto white balance,
continuous auto white balance and pre-set white balance.
The pre-set white balance can be set to 4000K, 4600K or 5600K.
The white balance of the AT-140GE is set under 7800K lighting in factory. When the camera is
started up at the first time, it is white balanced to 7800K and R and B gain settings are 0.
For executing the white balance, the entire image is
divided into 64 areas, 8 for horizontal and 8 for vertical.
The following drawing is an example of using a 2 x 2 area in the image center.
Continuous One push Manual
Tracking range 4000K to 9,000K 4000K to 9,000K 4000K to 9,000K
Adjustable range -6dB ～ +6dB -6dB ～ +6dB -6dB ～ +6dB
Store the setting value No Yes Yes
Note: In continuous mode, if the white part is not enough to make an adjustment, the white balance
may not achieve a proper white color.
Note: The completion of one push auto white requires a maximum of 5 seconds to complete.
Note: If the master gain is set less than 0dB, R and B gain can not be controlled up to -6dB. For
instance, if the master gain is set at -3dB, the saturation level of R and B gain is deteriorated
under 0dB.
9.4.3 Linear matrix
The AT-140GE incorporates a linear color matrix circuit to improve color reproduction.
As this circuit processes signals in the linear stage, before the gamma correction circuit, the
gamma circuit does not affect color reproduction.
This circuit has:
1. Linear
OFF
2. sRGB Standard which HP and Microsoft specify for printers and monitors. This preset
is based on this standard.
3. Adobe RGB Standard which Adobe systems specify. This preset is based on this standard.
4. User
User can manipulate R, G and B color relationships based on applications. Set
the gain for R-R, R-G, R-B, G-R, G-G, G-B, B-R, B-G, B-B to adjust.
Important Note:
If sRGB or Adobe RGB is used, please note the following procedure.
1) Achieve the white balance under the condition of D65 (6500K) illumination.
2) Gamma should be set at 0.45 and set the linear matrix at either sRGB or Adobe RGB.
3) Monitor should comply with sRGB or Adobe RGB color reproduction capability.
8
8
Windousize X :2
Window size Y :2
Window offset X :3
Window offset Y : 3
Setting example
Fig.29 White balance measuring area