Some techniques to try to avoid having too much light when you have long shutter speeds:
- If you shoot in shutter priority mode the camera will automatically decrease your aperture, but if you’re in manual mode you’ll need to decrease your Aperture in a proportional amount to the amount that you lengthen the shutter speed.
- Decrease the ISO, A higher number will make it more sensitive to light and a lower number will make the sensor less sensitive.
- Try a neutral density filter These filters cut down the light passing through your lens and into your camera which in turn allows you to use a slower shutter speed.