Tool description

The ND Filter Calculator helps photographers calculate the correct shutter speed when using Neutral Density (ND) filters. ND filters reduce the amount of light entering the camera, allowing for longer exposures in bright conditions. This tool automatically calculates the adjusted exposure time based on your original shutter speed and the strength of the ND filter you're using.

Features

  • Multiple ND Filter Options: Support for common ND filters from ND2 (1 stop) to ND1048576 (20 stops)
  • Comprehensive Shutter Speed Range: Choose from fast shutter speeds (1/8000s) to very long exposures (900s/15 minutes)
  • Exact Calculations: Shows both the exact calculated shutter speed and the closest standard camera setting
  • User-Friendly Display: Shows filter strength in both ND number and stops
  • Time Formatting: Automatically formats exposure times in seconds or minutes for readability
  • Instant Results: Real-time calculation as you adjust settings
  • Copy to Clipboard: Easy copy functionality for all calculated values

Use Cases

  • Long Exposure Photography: Calculate exposure times for creating motion blur effects in bright daylight
  • Waterfall Photography: Determine correct settings for silky smooth water effects
  • Landscape Photography: Plan exposures for removing moving people or clouds from scenes
  • Neutral Density Filter Shopping: Understand what different ND filter strengths will allow you to achieve
  • Education: Learn the relationship between ND filters and exposure time
  • On-Location Planning: Quickly determine settings before shooting

Supported ND Filters

  • ND2 (1 stop, 2x factor)
  • ND4 (2 stops, 4x factor)
  • ND8 (3 stops, 8x factor)
  • ND16 (4 stops, 16x factor)
  • ND32 (5 stops, 32x factor)
  • ND64 (6 stops, 64x factor)
  • ND1000 (10 stops, 1024x factor)
  • ND8192 (13 stops, 8192x factor)
  • ND32768 (15 stops, 32768x factor)
  • ND65536 (16 stops, 65536x factor)
  • ND1048576 (20 stops, 1048576x factor)

What is a Neutral Density Filter?

A Neutral Density (ND) filter is a piece of glass or resin that reduces the amount of light entering your camera lens without affecting the color of the image. Think of it as sunglasses for your camera. ND filters are measured in "stops" of light reduction - each stop halves the amount of light reaching the sensor.

How to Use

  1. Select Original Shutter Speed: Choose the shutter speed you would use without an ND filter
  2. Choose ND Filter: Select the strength of the ND filter you plan to use
  3. View Results: The calculator shows:
    • Your original shutter speed
    • The filter being used (with stops information)
    • The new calculated shutter speed (formatted for readability)
    • The exact value in seconds
    • The closest standard shutter speed available on most cameras

Example

If your camera's light meter suggests 1/250s without a filter, and you attach an ND1000 (10-stop) filter, the calculator will show you need a 4-second exposure to maintain the same exposure level. This long exposure would allow you to create smooth water effects or remove people from a busy scene.