@title Timelapse photo@param a For HDR timelapse movie
set:@param b JPG 640x480 + BKT@param c .@param m Interval (min)
@default m 0 @param s Interval (x60 sec) @default s 1 @param t
Number of takes @default t 300 @param x Initial delay (sec)
@default x 2 if t
