Aspects and embodiments provide a method of collecting a dataset representative of a specimen and an apparatus operable to perform the method. The method and apparatus use an optical sensor array configured to detect received electromagnetic radiation in a first optical channel and a second optical channel, an overlap region of optical electromagnetic radiation lying within both the first and second optical channels. The method comprises: selecting at least two discrete optical illumination bands of electromagnetic radiation such that after interaction with the specimen, the discrete optical illumination bands each lie within one of the first and second optical channel and outside the overlap region illuminating the specimen with the at least two optical illumination bands and collecting the at least two optical illumination bands after interaction with the specimen using the optical sensor array to form a dataset representative of the specimen. Such a method and apparatus recognises that filters used to chromatically and optically separate channels, for example, a red, green or blue channel are typically tuned to the response spectra of an image reproduction device to be viewed by a human eye. Such response spectra are often such that the channels substantially overlap, which can enhance a resulting image visually but may make any quantitative analysis of an optical imaging dataset representative of an object misleading. By tuning the illumination spectrum in accordance with the sensing device, it is possible to obtain useful quantitative results from standard imagine devices.Conformément à des aspects et à des modes de réalisation, linvention concerne un procédé de collecte dun ensemble de données représentatif dun spécimen et un appareil pouvant être utilisé pour réaliser le procédé. Le procédé et lappareil utilisent un réseau de capteurs optiques configuré pour détecter un rayonnement électromagnétique reçu dans un premier canal optique et un second canal optiqu
