Smartphone camera accessory maker Moment has updated its Pro Camera iPhone app with a dedicated slow shutter mode. Like most similar features in other apps, Pro Camera's slow shutter mode relies on computational imaging techniques including image stacking and blending rather than real slow shutter speeds. This means users can create the desired effects even in bright light without a need for ND-filters or other equipment.

There are separate settings for motion blur and light trail effects and users can shoot at shutter speeds of up to 30 seconds or in bulb mode. Shots are saved in the iPhone's Live Photo format which means they can be exported as a still image, GIF or short video clip.

Unlike the long exposure options on the Huawei P30 Pro and some other devices, the app does not correct for camera-shake during the exposure, so shooting from a tripod is recommended. More information and download links can be found on the Moment website.