Shutter Speed & Exposure

Exposure - What difference does shutter speed make?

Exposure refers to the duration (usually in seconds) that the image sensor or film if you're using a film camera. 

Using shutter speed to affect exposure:

This can be changed from the dial on the camera and normally is written like 1/400 and this represents 1/400th of a second. In most DSLRs this can be set from 1/8000 to 30 seconds. By using Bulb mode it can be even kept open for hours. 

Basically you will increase the shutter speed to allow less time for the light and decrease it to let light in for more time. 

These settings are for when you and your subject or whatever in your frame is stationary. In case of moving objects we will need to increase the shutter speed. Else we may blur the image. 

These images of a bird called Emu will help us understand the effect of shutter speed. 

The darker image was shot with a shutter speed of 1/250 and the brighter image with a speed of 1/40. ISO and aperture were constant. 

In the darker image the bird appears to be stationary, however that was not the case. Since the light entering the camera was for a shorter duration it only captured little of the details. 

I could barely see the bird and hence I decreased the shutter speed. This allowed me to expose the image to a level where everything could be seen. However in doing so I ended up with a blurred Emu. Since the bird kept moving the slow shutter speed did not help. 

You can also try playing with the shutter speed photographing both still images and moving ones. 

In my next post I will be writing about how Aperture affects exposure.

Kunal