“…Most of the articles (1)(2)(3)6,7,9,10,(13)(14)(15) have suggested illumination with studio lights, four suggested speedlight only (ring flash and dedicated TTL flashes (5,11) or unspecified speedlight (16) ), and two (17,18) did not mention the illumination source. Only four articles mentioned the three parameters used: ISO, aperture, and shutter speed (3)(4)(5)8) . More than half of the included articles did not mention these parameters (2,6,7,10,11,(13)(14)(15)(16)(17)(18)(19) .…”