Imaging Specification Of The Camera - Lacerta M-GEN User Manual

1.3.2 Imaging specification of the Camera

ADU means: Analog to Digital conversion Unit (step)
e - means: electron
RMS means: standard deviation (statistical); Root Mean Square
CCD active pixel area
Image conversion speed
Conversion (min. gain (2))
Readout noise at min. gain (2)
Readout noise at max. gain (9)
Average dark current
Operating temperature
1 the value is only informative but measured on some instances
2 at 23ºC CCD temperature
3 violating the limits is the responsibility of the User
The CCD and its environment heats itself a little bit if active (good for anti-dew).
The power dissapated in the HC is also rather useful than problematic.
4 typical value (mean) measured on 22 pieces of 'random' Camera instances.
The mean of deviation of this value between the instances is only 0.29 e
The
The gain of the CCD's analog output signal is called 'gain' generally and can be set in
the HC as a parameter. The scaling of this is defined so that 2 steps means one
magnitude difference in sensitivity. The full scale (from 2 to 9) cover 3.5 magnitudes
(×25). The table below shows the physical imaging parameters for each gain value
(approximately):
Min.
CCD pixel size
Imaging depth
(max. gain (9))
5.9
Pixel capacity 10k
-10
limits were measured in some "extreme" instances.
gain conversion
(e -
1
2
3
4
5
6
7
8
9
Note: gain 1 is not available from FW v2.00 due to
possible early pixel-saturation
Typical Max.
752 × 582
3.65 × 2.7
4.85 × 4.65
8
2M
44
1.75
22
7.1 8.5
3.2
60
pixel saturation
/ADU) (e - )
70.0 16700
44.0 10500
25.7 6660
17.5 4200
11.0 2650
7.0 1670
4.4 1050
2.77 666
1.75 420
7
unit Notes
pixel
mm
μm
bit
pixel/sec max.
e - /ADU 1
-
e /ADU 1
e - (RMS) 1
e - (RMS) 1,2,4
e - /px/sec 1,2
e - 1
°C 3
-
.