Chapter 2: Overview of NICMOS 2.1 Instrument Capabilities 2.2 Heating, Cooling and Focus 2.3 NICMOS Instrument Design 2.3.1 Physical Layout 2.3.2 Imaging Layout 2.3.3 Camera NIC1 2.3.4 Camera NIC2 2.3.5 Camera NIC3 2.3.6 Location and Orientation of Cameras 2.4 Basic Operations 2.4.1 Detectors’ Characteristics and Operations 2.4.2 Comparison to CCDs 2.4.3 Target Acquisition Modes 2.4.4 Attached Parallels