Wide Field and Planetary Camera 2 (WFPC2) is a two-dimensional imaging photometer which is located at the center of the Hubble Space Telescope (HST) focal plane and covers the spectral range between approximately 1150 to 10500 . ... Detection of faint targets will be limited by either the sky background (for broad filters) or by noise in the read-out electronics (for narrow and UV filters) with an RMS equivalent to 5 detected photons. ... The sections below give a more detailed overview. ...