A modular radiation integrator assembly including a radiation source that emits radiation, a first integrator module including a first input port and a first output port, an adjust tube configured to partially receive the first integrator module and engage the radiation source in a manner such that the radiation emitted by the radiation source travels to and enters the first input port, and a second integrator module including a second input port and second output port, the second integrator module couplable to the first integrator module outside the adjust tube in a manner such that the radiation exits the first output port and enters the second input port.