PWM (Pulse Width Modulation) dimming works by rapidly turning the LED on and off at a high frequency (typically 1kHz-40kHz), varying the percentage of on-time (duty cycle) to control perceived brightness. Because the LED runs at full current when on, color temperature remains stable across the dimming range, unlike analog dimming where color can shift at low levels. However, PWM at low frequencies can cause visible flicker, eye strain and headaches, and may cause stroboscopic effects with moving machinery. High-quality PWM drivers use frequencies above 3kHz (ideally above 10kHz) to be imperceptible. Analog dimming (constant current reduction) is flicker-free but may cause color shift at very low levels. Many modern LED drivers combine both methods for optimal performance. For camera and video environments, always verify flicker-free certification.