Here are all the details: -20mm is -10mm to the PASM which is -10mm to normal making normal + 20mm to the -20mm, but only +10mm to the PASM which is always + 10mm to the -20mm and -10mm to the non PASM oh and I forgot...-20mm is -10mm to PASM on normal mode and is -10mm to PASM on sports mode, Standard being +10mm to PASM on sport and normal mode....