ND Filter Calculator

Plan a Target Shutter Speed

Enter your correct metered exposure without a filter. Choose the shutter speed you want for the photograph, then fine-tune the recommended aperture and ISO to suit your available filter or shooting needs.

Metered Exposure Without Filter

Creative Goal

Fine-Tune Recommendation

Adjust aperture or ISO while keeping your target shutter speed fixed. The recommended filter updates immediately.

Nearby Available Filters & Stacks

Choose an ND Filter for a Target Shutter Speed

Start with a correctly metered exposure without a filter. In the planner above, choose the shutter time you want for the final image, then adjust aperture or ISO if needed. The recommended setup shows the closest practical ND filter for that exposure.

For example, moving from 1/1000s to 1s requires about 10 stops of light reduction, which corresponds to an ND1000 filter when aperture and ISO stay unchanged.

Stacking ND Filters

Filters can be combined by multiplying their ND factors, or by adding their stops. For example, ND8 + ND1000 = ND8000: 3 stops plus 10 stops gives 13 stops of reduction. The planner suggests a useful stack when a combination is closer to your required density than a single available filter.

Need to decide how much of the scene should be sharp before planning an exposure? Try the depth of field calculator.

Values are rounded to familiar camera shutter speeds. For very long exposures, use bulb mode, a remote release, and a timer.

Current Exposure Settings

ND Filter Selection

New Exposure Settings

How ND Filters Work

Neutral Density (ND) filters reduce the amount of light entering your camera without affecting colors. Each "stop" of ND filter halves the light, requiring you to compensate by:

• Slower shutter speed - Most common for long exposures (waterfalls, clouds)
• Wider aperture - For shallow depth of field in bright light
• Higher ISO - Rarely used, as it adds noise
• Balanced - Distribute the change across all three settings

ND Filter Reference