w and a table applicable to f t in the invention however it is made good enough for the invention only to memorize either one of the tables respectively applicable to f w and f t table 3 exhibits shutter speeds in the form of a table set on the basis of the iso speeds and the brightness information with respect to a lens f w this table covers from ev8 to ev17 and table 3 shows a part ev13 u02dc 16 thereof in table 3 the figures in the parentheses indicate the above mentioned segmented zones in terms of every 1 3ev step in the apex system table 3______________________________________ unit ms ev valueiso speed 16 3 15 6 14 9 13 12 ______________________________________25 0 9 20 11 30 14 00 17 6032 1 8 50 10 50 13 00 16 3040 2 8 00 9 80 12 20 15 2050 3 7 40 9 20 11 30 14 0064 4 6 90 8 50 10 50 13 0080 5 6 30 8 00 9 80 12 20100 6 5 84 7 40 9 20 11 30125 7 5 42 6 90 8 50 10 50160 8 5 10 6 30 8 00 9 80200 9 4 70 5 84 7 40 9 20250 10 4 38 5 42 6 90 8 50320 11 4 00 5 10 6 30 8 00400 12 3 68 4 70 5 84 7 40500 13 3 32 4 38 5 42 6 90640 14 3 00 4 00 5 10 6 30800 15 3 00 3 68 4 70 5 841000 16 3 00 3 32 4 38 5 421250 17 3 00 3 00 4 00 5 101600 18 3 00 3.