Here is a table with all the common filters a cinematographer is likely to come across. I have assigned I common filter factor for guidance only and would suggest you check the exact factor with the filter’s manufacturers before applying any correction.
Filter Factors (may vary slightly according to manufacturer)
where 0.3 = 1 stop and 0.6 = 2 stops, etc.
| FILTER | FACTOR |
|---|---|
| 85 | 0.2 |
| 85B | 0.2 |
| 85N3 | 0.5 |
| LL-D | minor |
| 81EF | 0.1 |
| N3 or ND3 | 0.3 |
| N6 or ND6 | 0.6 |
| N9 or ND9 | 0.9 |
| N12 or ND12 | 1.2 |
| POLARIZER | 0.6 |
| B-PM 1/2 | 0.15 |
| B-PM 1 | 0.2 |
| B-PM 3 | 0.4 |
| W-PM 1/2 | minor |
| W-PM 1 | minor |
| B-NET 1 | 0.15 |
| B-NET 3 | 0.5 |
| SEPIA 2 | <0.6 |
| 812 | 0.1 |
| CORAL 1/4 | 0.15 |
| CORAL 1/2 | 0.15 |
| CORAL 1 | 0.2 |
| CORAL 2 | >0.2 |
| CORAL 4 | 0.3 |
