How can you achieve a long exposure effect?

To achieve a long exposure effect, utilizing a slow shutter speed is essential. A slow shutter speed allows the camera's sensor to be exposed to light for an extended period. This results in the accumulation of light, which can create various artistic effects such as motion blur for moving subjects, smoothness in flowing water, or the capturing of light trails from moving vehicles.

The other methods mentioned, such as increasing the aperture size or using a fast shutter speed, are not suitable for creating a long exposure effect. A larger aperture allows more light into the camera but also alters depth of field, while a fast shutter speed captures light in shorter bursts, freezing motion rather than allowing for the gradual blending of light that characterizes long exposures. Adjusting ISO sensitivity affects the camera's sensitivity to light, but it does not inherently allow for longer exposure times. Instead, a higher ISO may enable shorter exposures in lower light, which is the opposite of achieving long exposure effects.