. 2015 Sep 2;10(9):e0135869. doi: 10.1371/journal.pone.0135869

Table 4. Comparison of Light Source Safety Maximum Permissible Emissions testing for the digital colposcopy systems.

System	L_B Blue Light Hazard (mW/cm²sr)	L_R Retinal Thermal hazard (W/cm²sr)
Leisegang Optik 2	239.7	24.0
5.0MP POCkeT Colposcope	4.61	0.52
2.0MP POCkeT Colposcope	4.78	0.48
Canon SX50HS^*	960.0^*	150.7^*
Apple iPhone 5S Flash	36.3	3.68

The limits for the exempt classification at subtended angle of 0.11 radians for L_B at 10 W/cm²sr and L_R 25.45 W/cm²sr.

* For digital cervicography with the Canon SX50HS at KCMC, the 150 W halogen source was used for illumination from the analog colposcope, the Wallach Tristar.