ND filter labeling

[Robert Spoecker]

I just ordered two neutral density filters and found them only listed by Filter Optical Density instead of F stop reduction.

We photographers all have an understanding of F stops, so why do manufacturers put optical density on their ND filters?

Yes, I now know that .3 means one stop reduction and .6 means 2 stops of reduction but it seems to me as a silly way to lable the filters.

Robert

[Canon Bob]

Whilst you may be using ND filters on your photographic equipment, others may be using them on telescopes, lasers, microscopy or projection equipment.....optical density is a good yardstick that works for all applications.

Bob