Stacked filter factor
Filter factors multiply, so stops add. Pick the filters you have on the lens to get the combined exposure compensation and a corrected shutter.
Add up all the filters on the lens at once — a polariser plus a yellow filter, for instance. Very dense stacks can affect colour and sharpness, so keep them sensible.
About this tool
Filter factors multiply, so the stops of compensation add up. Choose the filters you have stacked on the lens and this returns the combined factor, the total extra exposure in stops, and a corrected shutter speed.
How to use it
- Choose the first filter on the lens.
- Add any second and third filters you are stacking.
- Enter your metered shutter speed.
- Read the combined factor, total stops and corrected shutter.
FAQ
Do filter factors add or multiply?
The factors multiply, which is the same as adding the stops; a 2x and a 4x filter give 8x, or three stops total.
Any downside to stacking filters?
Thick stacks can cause vignetting, reflections and slight softness, so use only what you need.