I know this isn't directly about film processing and development but I can't think of a better place to ask this question: I have a Vivitar 285 flash that senses light returned to the sensor on the flash and adjusts the duration of flash to keep exposure constant. Has anyone tried using this automated feature to control fill flash? My concern is that bright ambient light will quench the flash too early.(posted 8876 days ago)I am planning to run a test on this for myself but was wondering if anyone had an opinion on this.