تنها مطلبی که از سایت کنون پیدا کردم. همون مد2 و زمانیکه شاتر زده میشه، فعال میشه
دوستان چون به انگلیسی مسلط هستند این متن رو انگلیسی میذارم که تمرینی هم داشته باشند.
Found on select Canon lenses and excellently suited for brilliantly sharp sports photography, Optical Image Stabilizer Mode 3 enhances Optical Image Stabilizer Mode 2 by functioning only when the shutter release is fully pressed. By remaining inactive until exposure, Mode 3 stabilization control allows for easy panning. Additionally, Mode 3 compensates shake in a direction perpendicular to the direction of panning when panning is detected and gives the equivalent effect of a shutter speed four stops faster.