When camera Pop up flash work as a master flash or flash trigger. The light may cause eyes blink or effect the exposure.
Aokatec A-N1& A-S1 IR Panel made by special material, it prevent visible light , only allow invisible IR light pass through.
Mount Aokatec A-N1or A-S1 IR Panel on hot shoe will reduces the brightness of the camera's built-in / pop-up flash and avoid eyes blink
A-N1 ------- for Nikon Canon Pentax Olympus Sigma SLR cameras
with Built in flash/ Pop up flash and standard hotshoe.
A-S1-------- for Sony SLR cameras with Built in flash/ Pop up flash and
Sony hotshoe. (A77 is exceptional)