Prime Focus Camera Manual: CCD Characteristics

CCD Characteristics (see also Plate Scale and Field of View)

PFCam's detector is a back-illuminated, Fairchild 4096 x 4096 CCD with 15-micron square pixels.

Quantum Efficiency Plot (measured in the lab, Jamuary 2006; opens in a new window).

Detector Characteristics for each readout mode

binning readout
speed gain
(e-/DN) readnoise
(e-) readout time
(m:ss) Linear to
(DN)

x1 slow 1.3 11 2:40 55,000

x1 fast 1.4 24 0:50 55,000

x2 slow 1.2 3.5 0:45 64,000

x2 fast 1.3 10 0:15 40,000

x4 slow 1.2 3.1 0:15 60,000

x4 fast 1.5 4.7 0:05 40,000

NB: Bias level should be about 1000 DN for every readout mode.
Measured on the telescope, August 2010 by E.Gates.

binning	readout speed	gain (e-/DN)	readnoise (e-)	readout time (m:ss)	Linear to (DN)
x1	slow	1.3	11	2:40	55,000
x1	fast	1.4	24	0:50	55,000
x2	slow	1.2	3.5	0:45	64,000
x2	fast	1.3	10	0:15	40,000
x4	slow	1.2	3.1	0:15	60,000
x4	fast	1.5	4.7	0:05	40,000
NB: Bias level should be about 1000 DN for every readout mode. Measured on the telescope, August 2010 by E.Gates.

Full well is reached at 118K e-, well beyond the 64K DN A-to-D saturation when using bin x2 slow readout, which is recommended for most data collection.

The default setup reads out the CCD using two of the chip's four amplifiers. The overscan regions occupy the far right (highest numbered) columns and correspond to the amplifiers as shown below (overscan regions not to scale).

More PFCam CCD specs and characeristics can be found on our detector pages.

Support Astronomers (sa@ucolick.org)

Last modified: Tue Mar 8 18:46:42 PST 2011

User's Guide to the Prime Focus Camera

Table of Contents

CCD Characteristics (see also Plate Scale and Field of View)