Systems for collecting light (e.g., in a flow stream) are described. Light collection systems according to embodiments include: a mount having an orifice for receiving light, an adapter configured for attaching a camera to the mount and a fastener for attaching a lens to the distal end of the mount and a releasably attachable connecter that is configured for coupling to an orifice plate and an aligner that is configured to couple with an aligner on the mount and maintain optical alignment between the mount and connector. Methods for coupling a connector and a mount are also described. Systems and methods for measuring light emitted by a sample (e.g., in a flow stream) are also provided.