A selectable threshold multimode gain control apparatus and method for a charge coupled device (CCD) or CMOS imaging system includes an automatic gain control (AGC) circuit which continuously controls gain in said CCD system to produce a mutually continuous combined target gain level. A processing system for an imager device includes a camera system for producing an imager signal, a correlated double sample (CDS) circuit for receiving data from an imager, a variable gain amplifier (VGA), an analog-to-digital converter (ADC) coupled to said CDS circuit, a digital gain circuit (DGC) coupled to said ADC, and an automatic gain control (AGC) circuit coupled to said DGC for controlling the CDS circuit and the DGC, as well as shutter timing for shutter gain.