I picked up a Tiffen orange #15. I think this is the older version of what now is their #16. When I meter through it with a pentax spot meter it shows a correction of 2/3 of a stop. I called tiffen to get a filter factor and they told me 1 2/3 stops. Could there be that much difference between what they claim and what my meter is telling me? Thanks, Robert
Yes a filter factor of 3 would be 1 2/3 stops as the tech at Tiffen said. But why when metering through the filter does it indicate only a 2/3 of a stop difference?