LIGHTING CONSIDERATIONS FOR THE IS32 OPTICRAM
The IS32 OpticRAM lends itself to profiling scenes and component parts by imaging the dimension to be measured onto a matrix of light sensors where each light sensor is equal to some distance in physical space.
The MicronEye Camera needs a high contrast scene in order to image the object into the IS32. Unlike a TV camera which can respond to shades of gray, the IS32 is a digital chip where each picture element makes a black/white judgement based on an arbitrary light level used as a threshold (trip light levee). Portions of the scene that are lighter than the threshold level will be judged as white while portions of the scene darker than the threshold level will be judged as black.
For example, if the trip light level is made lighter, then a new slice of the scene would be captured around that light threshold. One can look at-shades of gray as planes of binary light level slices. One example: 64 gray scales means 64 binary light level slices.
The trip light level can be changed in one of three ways:
Doubling the exposure time is the same as opening the f-stop by one stop, (changing the f-stop to the next smaller number), or in other words doubling the amount of light. Contrast can now be defined as a minimum difference between adjacent slices. Example: In taking 64 gray scale slices there is normally only one slice where the adjacent slice is of a minimum difference.
High contrast means that there are more than two adjacent slices that are about the same (usually three or more adjacent slices are about the same).