A charge coupled device imager, which can operate in time delay and integration mode, can be adapted to include variable columns having one or more blocking gates or other barriers that can be independently controlled and used to divide a used portion from an unused portion. The blocking gates may require less power to electrically insulate used from the unused sections. In this regard, an imager's charge handling capacity and dynamic range can be improved, while lowering CCD operating power requirements. Blooming drains can also be included to enhance the functionality of the imager and enable bidirectional imaging capability.