Page 256 - Fundamentals of Light Microscopy and Electronic Imaging

ELECTRONIC CAMERA CONTROLS 239

1.0 Newvicon
UV Chalnicon
IR Vidicon
Sensitivity ( A/ W) 0.01
0.1

Visible range
0.001
200 400 600 800 1000 1200 1400 1600 1800
Wavelength (nm)
Figure 13-5
The spectral responses of three commonly used video tubes. Video camera tubes vary in
their sensitivity to wavelength and luminance, depending on the composition of the target.
The Newvicon tube is sensitive across the visual spectrum from 400 to 850 nm and has a
peak sensitivity at 700 nm. Other tubes are relatively more sensitive to UV (UV-Chalnicon)
and IR (IR Vidicon) wavelengths. Video CCD cameras also have peak sensitivity in the
middle of the visual spectrum.

Luminance (lx)
10 –9 10 –8 10 –7 10 –6 10 –5 10 –4 10 –3 10 –2 10 –1 1 10 10 2

IR Vidicon

Newvicon, Chalnicon

Video CCD

SIT

Intensified video CCD

HCCD
Starlight Moonlight

10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 10 11 10 12 10 13
2
Photons/cm · s ( = 550nm)
Figure 13-6
Sensitivity comparison chart of detectors used in video cameras. The plot shows the
sensitivity ranges of various tube and CCD video cameras, a silicon-intensifier target (SIT)
camera, an intensified video camera, and a high-performance CCD (HCCD) camera.