The image sensor used by the MicronEye is comprised of dual 128 x 256 pixel arrays. If you remove the camera lens and look at the image sensor, you can clearly see the two arrays. Using the 1 ARRAY mode, only the image focused on the lower array is transmitted from the MicronEye. On the other hand, using the 2ARRAY mode causes both arrays to be transmitted from the MicronEye. The 2ARRAY mode has a split screen effect because of the spacing between the two arrays in the image sensor chip. In addition, the sensitivity to light of the two arrays is usually noticeably different. These two factors tend to make 2ARRAY mode inappropriate for many applications.