Hi Guys! Need your help... I'm still new to photography, I like landscape shots. My question is regarding ND filters. I have read that its great tool for landscape shot and that it reduces light so you can use longer shutter speed. I try and get one (ND8) but i can't really appreciate the final product. I use it in a bright sunny day. Any particular camera settings that I should try to have a good product? How long is the shutter speed that I need to use? :dunno:
thanks!
ND8 only reduces light by 3 stops. If you are taking in bright sunny day, it may not be enough.
Use the following steps to guesstimate what ND filter you will need:
1. Take a normal picture at the aperture that you would normally, at the time that you would, in the situation that you would.
e.g. f9 at ISO100 at 11am makes me take a picture without any filters at 1/150 secs.
2. Estimate how long exposure you would need.
e.g. I need the exposure to be around 3 secs
3. By that count, I would need something to slow my light by 3 * 1/(1/150) = 3 * 150 = 450 times.
This would approximate to a 9 stop filter. The closest are Hoya's ND400 (~9 stops) or B+W ND110 (10 stops).
If however I need my exposure to be around 15 secs for the same settings...
15 * 1/(1/150) = 15 * 150 = 2250 times...
I can still use an ND110, but make my aperture smaller by 2 to 3 stops (i.e. instead of f9, I will use f18) to get my 15secs shot.
Alternately, I can also stack a 10stop filter with a 3 stop (ND8) filter to get 13 stops.
You need to be clear on how to calculate f stops (aperture) and shutter speed, then the above calculations will make sense.