Laboratory equipment sold separately or as a unit for life science, multispectral imaging and polarized light imaging, namely, an imaging system primarily comprising computer software, computer hardware, monitors, cameras, optical couplers, optical polarizers, light filters and polarizing compensators for the measurement and analysis of stress, polarization, optical retardance, birefringence, and related properties of both macroscopic and microscopic samples, small animal imaging systems primarily comprising a digital camera and a tunable filter, used with lenses and fixed filters to obtain images of animal specimens, and computer software for use in operating the digital imaging system, controlling the stage and lenses, or interpreting the images obtained thereby, all of the foregoing sold separately or as a unit, digital imaging systems primarily comprising a digital camera and a tunable filter, used with microscopes or lenses to obtain images of samples or of natural scenes, and computer software for use in operating the digital imaging system, controlling the microscopes or lenses, or interpreting the images obtained thereby and adaptors for microscopes and lenses, all of the foregoing sold separately or as a unit, for optical imaging, digital imaging systems primarily comprising an illuminator, a digital camera, optical interference filters and a tunable filter, used for fluorescence optical imaging of samples, and computer software for use in operating the digital imaging system, or interpreting the images obtained thereby, computers, and adaptors for lenses and microscopes, all of the foregoing sold separately or as a unit for optical imaging; digital imaging system primarily comprising computer software, computer hardware, monitors, cameras, liquid crystal compensators, digital controllers, circular polarizers and light filters used for the imaging, measurement and analysis of spindles and birefringent structures