What is Super BLC  ( Super Back Light Compensation )?   

Super Back Light Compensation provides perfect exposure for an object in front of very strong back light, no matter if the main object is moving toward center ,upper, lower, left, right or any location in the screen.

MINTRON  ---  SUPER BLC ON
Excellent  exposure for main object no matter it in the center or on any corner  -   Super !!!
CENTER	LEFT	RIGHT
Good exposure	Good exposure	Good exposure

Other Maker  ---   LEGACY BLC
Exposure can be corrected only if main object is on the center   --   acceptable but not perfect
CENTER	LEFT	RIGHT
Wrong exposure	Good exposure	Wrong exposure

No BLC      ----    BLC   Off
Main object is under exposure while BLC was turn on   --  Honest camera but useless
CENTER	LEFT	RIGHT
Wrong exposure	Wrong exposure	Wrong exposure

A normal camera without super dynamic feature has only one option for shutter speed and Iris opening setting, for example, 1/60 sec. and F 2.0  for a selected scene. In case a very bright background or strong spot light behind a main object is unavoidable. In this case, the camera will take all incoming light average to them and decide the exposure index. This not a good way because as shutter speed increases and iris closes down, it will cause the main object become too dark to see. To overcome this difficulty, an algorithm called BLC (Back Light Compensation) is widely used in most of the cameras by using weighted zone theory. The image is first divided into 7 blocks or 6 zones (two of the zones are duplicated). Eeach of the zone can be weighted while calculating the exposure level. For example, the center portion can be weighted for 9 times more than all the other blocks, so the object in the very center of the scene will become more clear to see because the exposure is calculated mainly according to lighting level of center zone. However, there is a very big drawback. For example, if the main object is moving from center to up to down or left to right side of the scene, the object will become very dark because it is not discriminated so that it is not weighted.

The only way to solve the problem is to give a camera an intelligent that can instantly change weighted zone from the center to any portion of the screen and follow where main object is moving to.

MINTRON's alpha family cameras all are equipped with this excellent feature. The DSP first divides an image into 320X240 ( 76,800 ) tiny micro zones. Each zone scans and searches for a main object and over exposure pixel, those over exposure point is first been removed from calculation formula. the rest of the gray level area is then used for calculation of  the exposure level. The further search of the artificial intelligent is to give a proper weighting level by using a further adjustment to get a perfect exposure level.

Users may be astonished to see that the DSP can work so fast that no matter where the main object on the screen is moving to, the exposure level always follows immediately and provides a clear picture.