You may have seen pictures of waterfalls; lovely silky smooth water cascading over carelessly strewn rocks; the background of the picture dominated by a green mystical growth of coniferous trees. Sounds magical? Well it is difficult to get an exposure that is balanced out so perfectly without any special tools, especially when considering the fact that the light in such conditions can be outrageously uneven and difficult to manage. I am not referring to Photoshop or any such photo editing tools, as such effects are difficult to achieve with these. This is where filters come into the picture.
When buying filters there are a few factors which you should look into
First off, think of them as shades, but for your camera. They come in different strengths of stopping power such as ND2, ND4, ND8 and so on. A ND2 filter will have a stopping power of 2. In other words it will allow half the amount of light that reaches your camera sensor. As you keep increasing the power the light gets halved. So a ND8 filter will stop 87.5% of the light.You will also need to know the filter thread specification.Filters are designed to match the filter thread specification of the lenses. Look at the front of the lens and locate the number to know the size you need. There should be a sign like this - ⌀ either preceded or followed by a number like this - ‘58’. When buying a filter ensure that the filter thread specification mentioned on the filter matches that of the lens.