An instrument for processing and/or measuring a biological process comprises a plurality of filter assemblies configured to be interchangeably located along at least one of the optical paths. The plurality of filter components includes a first filter assembly characterized by a first optical power and a first filter having a first filter function, the first filter function characterized by at least one of a first low-pass wavelength or a first high-pass wavelength. The second filter assembly is characterized by a second optical power and a second filter having a second filter function, the second filter function comprising at least one of a second low-pass wavelength that is different than the first low-pass wavelength or a second high-pass wavelength that is different than the first high-pass wavelength.