Long exposure photography transforms moving elements into something the eye cannot ordinarily see. Flowing water turns to silk. Clouds streak across the frame in dramatic arcs. The technique is straightforward once you understand the variables involved.

The Fundamentals

A long exposure is any shot where the shutter stays open long enough for moving elements to blur while stationary elements remain sharp. For landscape work, this typically means exposures between 1 second and several minutes.

The three things you need: a sturdy tripod, a way to reduce light entering the lens, and a remote shutter release or timer to avoid camera shake.

Choosing Your Shutter Speed

Different shutter speeds produce different effects, and the right choice depends on the speed of what is moving.

Water:

  • 1/4 to 1 second: Slight smoothing, retains some texture in rapids and waves
  • 1 to 5 seconds: Classic silky look for waterfalls and streams
  • 15 to 30 seconds: Complete smoothing of ocean waves into a misty, ethereal surface

Clouds:

  • 15 to 30 seconds: Slight streaking, works well with fast-moving storm clouds
  • 1 to 3 minutes: Dramatic streaks that convey strong directional movement
  • 5+ minutes: Almost complete abstraction, best reserved for very specific compositions

These are starting points. Wind speed, water flow rate, and the focal length of your lens all influence the final result. Shoot test frames and adjust.

Neutral Density Filters

In daylight, you cannot achieve multi-second exposures without drastically reducing the light reaching your sensor. This is where neutral density filters earn their place in your bag.

A 6-stop ND filter turns a 1/60s exposure into roughly a 1-second exposure. A 10-stop filter turns that same 1/60s into about 15 seconds. For most daytime long exposure work, a 6-stop and a 10-stop filter will cover nearly every situation.

Calculating exposure with ND filters: Start by metering without the filter. Note your base exposure. Then apply the filter and multiply the shutter speed by the filter factor. A 6-stop filter multiplies by 64. A 10-stop filter multiplies by 1024. Most photographers keep a reference chart rather than doing mental math in the field.

Watch for color casts. Cheaper ND filters often introduce a warm or magenta shift. This is correctable in post, but it is worth knowing about your specific filters so it does not catch you off guard.

Camera Settings

Set your camera to manual mode. Choose your composition and focus before attaching the ND filter, since heavy filtration makes the viewfinder too dark to see through. Lock focus by switching to manual focus after acquiring your focal point.

Use your lowest native ISO, typically 100 or 64. Stop your aperture down to f/8 or f/11 for optimal sharpness across the frame. Avoid going beyond f/16, where diffraction begins to soften the image.

Enable long exposure noise reduction in camera if your exposure exceeds 30 seconds. This doubles the capture time since the camera takes a dark frame for noise subtraction, but the cleaner file is worth the wait.

Shooting Technique

Use a cable release or the camera’s 2-second timer to trigger the shutter. Even pressing the button gently introduces vibration on a tripod.

If your exposure exceeds 30 seconds, switch to Bulb mode. Hold the shutter open for the calculated duration using a cable release with a lock, or use an intervalometer with a set time.

Cover your viewfinder eyepiece during very long exposures. Light leaking in through the back of the camera can create unwanted artifacts, especially with exposures beyond a minute.

Working with the Conditions

The best long exposure images are not just technical exercises. They work because the movement adds something meaningful to the composition. Silky water draws the viewer’s eye along a riverbed. Streaking clouds create a sense of passing time above an ancient mountain.

Pay attention to what the movement is doing in relation to your static elements. The contrast between motion and stillness is what gives these images their power.