CAM04 (spectrophotometry) was designed for stepwise imaging across the wavelength ranges of spectral features, such as dust bands, complex molecules, or gas emission lines, as well as for spectral imaging scans across virtually the full wavelength range covered by the camera. A spectrum was obtained by following a given sky pixel or region through a series of narrow-band images. A complete CVF spectrum took at most 115 steps in the short wavelength channel and 85 for each of the CVFs which together spanned the long wavelength (LW) channel.
The basic observing parameters were the same as for CAM01 though the wavelength range of the spectral scan and the CVF increment that detemined the wavelength step had also to be specified. The command logic then determined the initial (`begin') and final (`end') positions of the filter wheel closest to the requested wavelength range limits, and scanned between these positions at `step number' intervals. A scan was always done with the same overall optical configuration of the instrument. However, within the same TDT it was always possible to perform several scans in different overall instrument configurations (channel, pfov, wavelength range, step number interval).
The spectrophotometric (CVF-scanning) mode could not be used with beam-switch or in a celestial raster map although individual CVF positions could be used in the modes CAM01 and CAM03 described above.