No, this will not help. Thermodynamic law forbids this. Otherwise one can create a machine concentrating all the thermal radiation of one black object at tempe

No, this will not help. Thermodynamic law forbids this. Otherwise one can create a machine concentrating all the thermal radiation of one black object at temperature T1, onto another perfectly white object also at T1 with a tiny black hole, heat up the second and then violate the second law of thermodynamics. Keyword for further Googling: etendue