ETFP (A), PTSA (B) and E&P&EP(C) in relation to sun exposure time and pain intensity. The lines represent identical values (iso-score lines); the exact values are given in the legend on the right side. Examples given in the text serve to improve the readability. ETFP has a better discriminatory power at long exposure times, whereas PTSA has better discriminatory power at short exposure times. E&P&EP has a nearly identical discriminatory power over the whole range of exposure and pain scores.