Abstract: A camera includes a charge-coupled device (CCD). The CCD has an anti-stokes phosphor bound to the light receiving surface of the CCD. The anti-stokes phosphor emits electromagnetic radiation having wavelengths in the range of 950 nm to 1100 nm. A housing surrounds the CCD and defines a filtered aperture through which, in use, light can pass and be received by the phosphor CCD.

Abstract: A method for observing the presence of at least one fluorophore in a test material using a detector comprises the steps: a) allowing incident ultraviolet light to pass through an exchangeable wavelength conversion screen comprising a scintillator which absorbs light of ultraviolet wavelengths and emits light of a narrow band width ?s1-?s2 whereby the transmitted light has wavelength in the range ?s1 to ?s2; b) allowing transmitted light to pass into the test material which comprises a fluorophore which absorbs light at an excitation wavelength around a maximum ?dx, in which ?s1<?dx<?s2, and emits light at a wavelength ?dm whereby the fluorophore emits light at said wavelength ?dm; and c) detecting emitted light using a detector system which is sensitive to light of wavelength ?dm. The scintillator is suitably thulium doped yttrium vanadate and the fluorophore is preferably fluorescein.

Abstract: A camera comprises a charge-coupled device (CCD). The CCD has an anti-stokes phosphor bound to the light receiving surface thereof. A housing surrounds the CCD and defines a filtered aperture through which, in use, light can pass and be received by the phosphor CCD.