Table 3.

Comparisons of several types of spectral scanning cameras. AOTF, acousto-optic tunable filter; LCTF, liquid crystal tunable filter; FTIS, Fourier transform imaging spectrometer; FPI, Fabry–Perot interferometer; FWHM, full-width at half-maximum (measured in nm). Wavelengths refer to the operating range of wavelengths. VIS, visible wavelengths (400 to 700 nm); NIR, near-infrared wavelengths (700 to 2000 nm). Switching speed refers to time to change from one wavelength to another one; ms stands for milliseconds (1/1000 s).

Type	Wavelengths operating range	FWHM (nm)	Number of bands	Switching speed
Filter wheel	VIS-NIR	30 to 250	<50	$\sim 1\mathrm{s}$
LED-based	VIS	20 to 70	<100	$\sim 500\mathrm{ms}$
AOTF	VIS-NIR	2 to 6	>1000	$\sim 1\mathrm{ms}$
LCTF	VIS-NIR	5 to 30	>1000	$\sim 100\mathrm{ms}$
FTIS	VIS-NIR	10 to 50	>1000	$\sim 10\mathrm{ms}$
FPI	VIS-NIR	10 to 50	>1000	$\sim 10\mathrm{ms}$