ND filter
calculator
Meter without the filter, then pick the filter you screw on. You get the new shutter speed, and a countdown when it's longer than 30 seconds and needs bulb mode.
Meter and focus first, then screw the filter on. 1/3 stop per step.
Filter
Second filter, stacked
Stops add up when you stack filters: a 6-stop and a 3-stop make 9.
New shutter speed
- Filter strength
- Exact time
- Camera mode
Bulb countdown
0:00
Open the shutter and press Start together. It beeps and vibrates when it's time to close.
Filter names
Makers label the same filter three ways. ND1000, ND 3.0 and "10 stops" are one filter: the ND number is how many times longer the exposure gets, the density adds 0.3 per stop, and each stop doubles the time. The shutter speed chapter explains the counting.
Before you open the shutter
- Use a tripod and a remote or the self-timer, so pressing the button doesn't shake the camera.
- Switch to manual focus after focusing, so the camera doesn't hunt in the dark.
- Cover the viewfinder on a DSLR. Light coming in the back can fog long exposures.
- With long-exposure noise reduction on, the camera takes a second exposure of the same length afterwards. Wait for it before moving.