ISO

ISO originated from film speed ratings where higher ISO film was more sensitive to light but produced more visible grain. Digital ISO works similarly — raising ISO amplifies the sensor signal, brightening the image but also amplifying noise. Low ISO values like 100-400 produce clean images with minimal noise. High ISO values like 3200-12800 enable shooting in dim conditions but introduce visible noise that degrades detail and color accuracy. Modern cameras have improved high-ISO performance dramatically, but noise remains a fundamental trade-off. AI denoising tools like those in Magic Eraser can clean up high-ISO noise in post-processing, recovering detail that would otherwise be lost to noise artifacts.