Shutter Speed and S Mode

Shutter speed refers to the duration for which the shutter in front of the image sensor remains open. While the shutter is open, the image sensor is exposed to light, and an image is formed accordingly.

The diagram above illustrates shutter components of an E‑mount camera. The shutter in [1] is open, exposing the image sensor to light. The slower the shutter speed, the more light reaches the image sensor. For instance, changing the shutter speed from 1/60 s to 1/30 s doubles the incoming light volume.

Alongside the aperture, which controls the light passing through the lens, shutter speed is one of the key factors determining exposure.

In automatic shooting modes (namely P mode and A mode), the camera automatically sets the shutter speed. In S mode, you may configure the shutter speed manually as preferred.

How Shutter Speed Affects Photographs

You can manipulate shutter speed to create different visual effects in your shots. The sample images below demonstrate results achieved with varying shutter speeds.

These waterfall photos were captured at different shutter speeds. Image [1] was taken at 1/1250 s, the fastest setting among the three. With an extremely short open duration, it freezes the motion of the flowing water completely. Image [2] was shot at 1/20 s. As the water keeps flowing while the shutter stays open, the photo delivers a stronger sense of motion. Image [3] was captured at 1/4 s, the slowest shutter speed used. The lengthy exposure turns the running water into a silky texture.

This technique lets you capture moving subjects in diverse ways. Desired shutter speeds can be configured under S mode and M mode, though the available speed range varies by camera model.

If you intend to freeze fast‑moving subjects, such as sports scenes, it is recommended to use the fastest available shutter speed to avoid motion blur.

The photo above was taken at 1/4000 s, successfully freezing the moment the athlete attempts to catch the ball. Conversely, slower shutter speeds are suitable for recording water streams or light trails.

The example above used a 5‑second shutter speed to capture fireworks trails. Nevertheless, slower shutter speeds make images more prone to blurriness. Shooting in low‑light environments such as fireworks displays and night scenes usually triggers slower automatic shutter speeds, so a tripod is required to stabilize the camera.

When a tripod is unavailable, you can raise the ISO sensitivity to enable a faster shutter speed. Bear in mind that higher ISO values are likely to introduce image noise. For handheld night photography, the Handheld Night Scene mode is a recommended option.

The photo above suffers from blur caused by camera shake under a slow shutter speed. When shooting moving subjects, you need to watch out for both camera shake and subject motion blur. Movement of either the camera or the subject will result in blurred, unclear footage.

S Mode (Shutter Priority Mode)

S Mode (Shutter Priority Mode) allows manual configuration of shutter speed. Within this mode, the camera automatically adjusts the aperture (F‑value) and ISO sensitivity to achieve properly exposed images.

This mode is ideal if you want to freeze moving objects or record trails of water and light.