M43 System
Live Composite
An OM System in-camera shooting mode that combines multiple long exposures into a single image, adding only light that is brighter than the base exposure. Used for light trails, star trails, and lightning without overexposing the sky or background.
Live Composite is a shooting mode exclusive to OM System and Olympus Micro Four Thirds cameras. It captures a continuous series of exposures and merges them in real time, displaying the result on the rear screen as it builds. Unlike a conventional long exposure, Live Composite adds only pixels that are brighter than the corresponding pixels in the base exposure. Areas of the frame that remain at the same brightness as the base — the sky, a static background, a foreground subject — do not change in brightness regardless of how long the composite runs.
This behaviour solves a specific problem in long exposure photography. A conventional 20-minute exposure will overexpose the sky and any lit areas. Live Composite can run for 20 minutes and produce a correctly exposed sky with accumulated light trails, star trails, or lightning strikes added on top, because those transient bright events are the only thing being added to the base image. The photographer watches the result build on screen and stops the composite when satisfied with the accumulated light.
Live Composite is set up by choosing a base exposure time — typically between 1 second and 60 seconds — and the camera takes that exposure as a reference. Every subsequent frame of the same duration is compared to the reference, and only pixels that exceed the reference brightness are blended into the output. The mode is accessible through the SCN or dedicated drive menu on compatible OM System bodies including the OM-1, OM-1 Mark II, OM-5, OM-3, and earlier Olympus PEN and OM-D bodies.
Common uses include car light trails on roads, star trail accumulation over hours, lightning captures during storms, and sparkler photography. For light trail work, a base exposure of 2 to 4 seconds is typical, run for as long as needed to capture sufficient trails. For star trails, a base exposure of 15 to 30 seconds run over one to several hours produces smooth circular arcs. The feature is one of the most distinctive capabilities of the OM System platform and has no direct equivalent in Panasonic M43 cameras.