The NIR-Block provides those UV photographers who use stacks of ionic filters the opportunity to achieve a new maximum in NIR (Near-Infrared) blocking while still enjoying excellent UV transmission. In the NIR-Block we have exceeded the UV transmission of the Schott S8612 while also providing significantly greater out-of-band blocking.

UVROptics' CuRB is an acronym for our Copper (Cu) Red-Blocking filter. The CuRB is a water-tight cell, within a 52mm filter ring, containing a Copper sulphate (CuSO4) solution at a precise concentration. The CuSO4 blocks, through absorption, the high-red and Infrared wavelengths in the 670nm-1100nm range.The advantage of the CuSO4 over other Infrared blocking filters is the UV transmission of Copper sulphate as well as the red/NIR blocking beginning in the 690nm range. A UV photographer can use any of the common UV-transmitting, visible-light-absorbing filters, e.g., UG1, UG11, ZWB1, in conjunction with the CuRB to produce an IR free image.