What is an ND filter? What is it for? And why do you need it?
While you can do a lot in the post production nowadays, one thing cannot be replicated and requires ND filter – slow shutter movement in a bright light. Everyone knows how cool photos with long exposure look – these blurry rivers of light on the freeway, or a name written out of thin air by the glow stick. For these shots you leave your shutter speed open for 5-10 seconds of time, the setting that is impossible to shoot with in a broad day light without having your photos looking overblown or just completely white. And that is when ND filter comes in handy.
In today’s quick tutorial based on “Two Minute Tips” episodes with David Bergman, we learn what ND filter is for, what kinds of it are available, and how you can implement it in your photography.
What is ND filter?
“ND” stands for neutral density. ND filter blocks the light from going through lens and hitting the camera sensor. When using ND filters, you can shoot the movement of (in this example water) anything with a long exposure and get that great smooth flowing effect.
ND filters come in different strengths. For every .3 it blocks 1 stop of light. So if you have a filter with the strength of 3, it will block 10 stops of light.
ND filters come in a fixed and a variable format. Fixed format filters have only one, certain strength number that never changes – kind of a prime lens in analogy. Variable filters on the hand are like zoom lens – you can spin it to adjust the density of the filter. While it is more convenient to have a variable filter, there are some trade offs. Fixed filters are usually cheaper and produce better quality images. Whereas variable filters might have an X – shaped shadow, especially when used on a wide lens.
What is ND Filter for?
If you want to shoot with a very slow shutter speed or wide open aperture in day light, ND filter is the only solution currently on the market. Another handy feature that is not related to its direct application – ND filter can protect your lens from dust or scratches! Since you screw it on your lens, in a potentially harmful situation that can damage your lens it is the filter that will take the hit.
Watch the full episode with David Bergman and Adorama TV: