Red filter terminology

[sothoth]

Stupid question: If a red filter is referred to as "3x" does that mean you need to increase exposure 3 stops to compensate for lower light?

 

[sothoth]

Oh, and how high do they go if my assumption is correct?

 

[Chris of Arabia]

Try this page to establish the settings needed - filter factor

The 3x means that you need three times as much light as compensation, not 3 stops (which would be 8x as much). In your case, you need to open up by 1 2/3 stops.

 

[sothoth]

The 3x means that you need three times as much light as compensation, not 3 stops (which would be 8x as much). In your case, you need to open up by 1 2/3 stops.

Perfect... thanks a lot.