Complementing the optical attributes, this lens also incorporates a four stop-effective optical image stabilization system that minimizes the appearance of camera shake for sharper handheld shooting. A ring-type Ultrasonic Motor (USM) also affords quick and accurate autofocus performance, along with full-time manual focus override for fine-tuned control. Additionally, as with all L-series lenses, this 85mm f/1.4 has a dust- and weather-resistant construction, as well as a fluorine coating on exposed elements, to benefit its use in harsh environmental conditions.