EIS is software-based image stabilization that crops video and shifts frames to compensate for motion. All phones have EIS; it's less effective than OIS but requires no hardware.
EIS mechanism: video is cropped inward by 5–15%, then frames are digitally shifted to align previous motion vectors. The crop area absorbs vibration; viewers see stable image.
EIS advantages over OIS: No moving parts: no mechanical wear, lower cost, more reliable long-term. Works across all focal lengths: lens shift OIS only stabilizes one focal length; EIS stabilizes macro, wide, and telephoto equally. Low power: pure software, minimal CPU/GPU overhead.
EIS disadvantages: Crop penalty: 10–20% resolution loss (4K video becomes effectively 3K) Latency: 1–2 frame lag before stabilization activates; first frame often shaky. Artifacts: aggressive EIS causes "rolling shutter" distortion on panning, warping on fast motion. Less effective: compared to optical OIS on extreme motion.
OIS + EIS combined (hybrid): best approach. Phone uses OIS for primary stabilization, EIS as secondary fine-tuning. Minimal crop, maximum stability.
Video-specific: EIS (and OIS) matter much more for video than stills. For photos, fast shutter speed is the best stabilization.
When to prioritize EIS: mostly phones do this adequately for casual video. Videographers shooting handheld benefit from OIS-enabled telephoto + quality EIS processing.
Comparison: expensive camera stabilizers (gimbals, sliders) achieve superior results, but EIS + OIS on flagship phone rivals basic stabilizers for casual use.