The present invention provides a system for extension of dynamic range and contrast of a video capture under fluorescence imaging conditions using a single detector. For this purpose, the system (100) comprises of a light engine (107) which sequentially switches between a high-intensity fluorescence excitation light mode (107A), a low-intensity fluorescence excitation light mode (107B) and NIR reflectance light (107C). Correspondingly, a detector (103) captures three data streams—High Intensity Fluorescence Data (105A), Low Intensity Fluorescence Data (105B) and NIR Reflectance Data (105D). A scene processing unit (105) then processes the three data streams and generate two additional data streams—a Wide Dynamic Range Fluorescence Data Stream (105C) and an Enhanced Vascular Index Data Stream (105E). The system also uses a Selective Visualization Unit (106) to allow the user to visualize any of five data streams.