Image Stacking

Available modes

Open Image Stacking in the TopBar. The selector offers Light Trails, Motion Blur, Double Exposure and Focus Bracketing according to lens support.

Light Trails: draw with motionNew

Select Image Stacking → Light Trails. Mount your iPhone on a tripod and frame headlights, moving lights or light painting. Adjust exposure before starting. One tap on the shutter starts capture; another ends it immediately. Cancel discards the capture; the automatic limit is five minutes.

The mode preserves brighter trails as lights move. Enable the stacking preview to follow the accumulated result. Keep the camera still: this mode does not align frames. Noise and intersecting colors can affect the result.

• The result requires at least one second and five valid frames. Resolution comes from the video stream, limited to 4096 pixels on the longest side. Leaving the camera or sending the app to the background cancels the sequence.

Motion Blur: soften movement

Motion Blur uses a temporal average with global alignment to simulate a long exposure. Moving elements can blur while stable areas remain more defined.

The result depends on duration, stability and scene. The preview is a reference; check the exported composition.

Double Exposure: two shots

Take the first photo, reframe using its overlay in the preview and shoot again. The mode explicitly waits for the second exposure. The two frames are not aligned: element placement is part of the composition.

Images are added as light in linear space and receive a curve for SDR output. Default internal compensation of −1.5 EV leaves headroom for highlights. Interface EV affects camera exposure before each shot and is independent of this compensation.

• During the sequence, orientation, lens and other controls are locked; shutter, Cancel and EV remain available.

Saving, effects and cancellation

The composition can receive LUT, grain, halation, cropping and project organization. The result is exported as HEIF or JPEG.

Save original without effects preserves the composition before effects, not the frames used to build it. RAW, Live Photo, Portrait, flash and general manual controls follow mode restrictions. Intermediate files are removed on completion, failure or cancellation.

Limits and validation

Alignment attempts to register global camera movement; it does not correct all local scene movement. Check for artifacts in water, people and moving objects. Perspective changes and low texture may prevent registration.

Quality, cancellation, memory pressure, low storage and camera resumption need validation on a physical device.