I already posted some of this years back in my old blog and… well here there are… again… no ND filter used as you can see only low ISO setting and with a narrow aperture (so a high number like f/22), the depth of field is much greater, which is useful for things like landscape photography – it will limit the amount of light reaching your sensor, so you will get slower shutter speeds, which makes a tripod handy. Ah yes and a remote shutter…
Well normally you “should” use a neutral density filter which blocks out light without leaving a colour cast on the resulting image. Each ‘stop’ of an ND filter reduces the amount of light entering the camera by a factor of 2 so:
- 1 stop = 21 = 2 = ND2
- 3 stops = 23 = 2 x 2 x 2 = 8 = ND8
- 10 stops = 210 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 1024 = ND1024
A common ND4 reduces the amount of light hitting the sensor by a factor of 4. A ND8 filter by a factor of 8 also 3 stops, with a 10-stops the light is being reduced by a factor of 1024, means that the shutter needs to be open for over 1000x longer than without the filter.
Whilst this is the reason that you get silky smooth water or clouds rushing across the sky, it is also the reason why your workflow will need to be adapted to overcome some issues as a result of the huge reduction in light.
If you like to shoot architecture but you hate that the people are walking around there an ND filter may be helpful in getting rid of them…
A tripod is considered a necessary requirement for landscape photographers and guess what it is even more important when shooting with a 10-stop filter. Exposures that extend more than a couple of minutes need a tripod as sturdy as it can be. So you need to ensure the legs on firm ground, not extend the centre column and take off the camera strap or secured it in order that it is not moved by the wind.
Compose and focus your shot without the filter, switch to manual focus and then carefully attach the filter. This way the lens will not hunt for focus when you press the shutter.
Even at low ISO very long exposures can introduce noise in the form of hot pixels… and well shoot in RAW.