View Full Version : Filter Factor

Jerry Cunningham
4-Oct-2006, 16:51
I purchased a used yellow Hoya filter. It is marked Y(K2). Does anyone recall what the filter factor is on that item?
Jerry Cunningham

Robert Ley
4-Oct-2006, 17:48
Filter factor of 2, one stop increase of exposure.

Jerry Cunningham
4-Oct-2006, 18:36
Thanks Robert

Andrew O'Neill
5-Oct-2006, 07:15
It can also depend on what film you use. I never follow published factors...they are general numbers, like factors for reciprocity effect.

Helen Bach
5-Oct-2006, 14:17
A Wratten 8 (K2) has about 90% transmission over most of the spectrum, so you can use less than one stop, depending on the effect you want.