Filter Calc

Neutral Density filters can help add an interesting aspect to your photography. One drawback with very dark filters is that they often exceed the camera's ability to provide an accurate exposure reading. Filter Calc is a javascript based application that takes your metered exposure value and returns the proper exposure time with the filter taken into account.

To Use Filter Calc:

Select your filter type and click Go.

 

On the resulting screen select the shutter speed that most closely matches your camera's meter with the filter removed.

 

Click Caclulate to determine the appropriate shutter speed, install the filter and expose.