In article <32F6CB7D.6CD6@ix.netcom.com>, mathison@ix.netcom.com says...
>RAPropper wrote:

>> It's been a long time since I used B&W filters. I just bought a red 25A
>> filter with a filter factor of 8.
>> Does this mean 3 stops wider than normal?

>Yes. However the simple way to prove this is hold the filter in from of
>a meter and see what happens.

8 (3-stops) is correct (for most films), but reading through
the filter is likely to give a different result... (due to
color sensitivity error in the meter and/or film).
Hope This Helps