09-16-2015 04:30 PM
09-16-2015 08:02 PM
Commonly it's a 10-stop filter for these long exposure stops. If the filter is listed in "density" values then each "0.3" worth of density is equal to 1 stop of exposure (0.1 is 1/3rd stop). That means you'd be looking for an ND 3.0 filter.
One quirk... the filter is so dark that you cannot see to compose, focus, or get an exposure reading. This means you do all that with the filter removed, focus, get a meter reading (in manual mode) then turn off the auto-focus, insert the filter, manually increase the exposure by 10 stops before taking the shot.
I have a B+W ND 3.0 thread-on filter as well as a Lee "Big Stopper" filter (slide-in type).
In "Sunny 16" conditions it would take you from f/16 at 1/100th (ISO100) down to a 2 second exposure. (an 8-stop would only take you down to 1/2 sec.)
09-16-2015 08:07 PM
I have no personal knowledge of the product, but an Amazon reviewer said it has a strong color cast. That is a known problem with many less expensive ND filters. Getting the "neutral" into "neutral density" seems to require a higher quality product.
You can Google reviews and make your own determination if no one on the Forum has any direct experience.
09-17-2015 01:31 AM