I love to make long exposure photographs.  I love to take my time when creating the image and seeing what the passage of time looks like in a single image.  For me, when looking at the images, they are almost dream like and have a calming effect.  

So how do we create these long exposures?  We need to make less light hit the sensor and we do that in a few ways.  First by adjusting the camera. 

  1. Low ISO – 100 ISO works great. This makes the camera not amplify the amount of light it sees.  More on ISO can be found HERE.
  2. Close down the aperture – f/16-f/22. this makes the hole in the lens small for less light to come through.  More on aperture can be found HERE.  

Now we need to make even less light come through the lens, this is where our NEUTRAL DENSITY FILTER comes in.

A neutral density filter will cut the amount of light coming through the lens without affecting the color, allowing you to photograph with a slower shutter speed than normally required.

Solid neutral densities come in many different levels of darkness, anywhere from 1 stop (cutting out 1/2 the light) to 16 stops (cutting the light to 1/100,000th of the original amount)

Distinguishing these filters gets confusing because different companies use different ways of telling you what you are getting.  Here is a fancy little chart to help you out:

What do you need:

  • Camera with manual adjustment of shutter speeds and bulb mode
  • Lens that you can screw filters on or a filter holder can be attached
  • Cable release –  you need to be able to release the shutter without moving the camera
  • Tripod
  • A neutral density filter

What you need to do:

1. Set your camera up on your tripod

2. Take a test shot without a filter so that you know the correct exposure without the filter and you can decide on your composition

3. Lock in focus. Switch your lens to manual focus because it can be very hard for your camera to focus with a dark filter in front of it.

4. Add your ND

5. Calculate your exposure. For this you need the shutter speed from your test shot and you need the number of f-stops that your filter reduces.

If you don’t want to do all of that, there are plenty of great apps out there that will do the math for you. I like ND Filter Expert, it is easy to use and you can even stack multiple filters.

6. Switch your camera to Bulb mode and set a timer, or some cameras have a T mode where you can set the exact amount of time that you want.

7. Cover the viewfinder if u have a DSLR. Light can leak in and ruin your photo. Some camera companies make small plastic inserts for this. You will not need to worry about this with mirrorless because the viewfinder does not see through the lens.

8. Use your cabled shutter release in bulb mode and lock the button in position

9. Relax while you create beautiful photographs 🙂

All images and text by Melinda Walsh