Which filter should you use – if any – for Landscape Photography? It’s a question I hear all the time. Perhaps one of the most overlooked and undervalued tools you can own as a photographer is a Neutral Density filter (ND Filter) or Graduated ND Filter. In fact, if photography is considered painting with light then a ND filter would be considered the brush tip. You see, different paint brush tips can be used to regulate, if you will, the amount of paint you apply with each stroke – just like different Neutral Density or Graduated ND filters can be used to regulate the amount of light you allow to enter your camera.
A Neutral Density filter reduces the intensity of all wavelengths or colors of light equally. That’s just a fancy way of saying it lets less light into your camera. They come in different intensities and styles. One such style is the Graduated Neutral Density filter which blocks light on half of the filter, and gradually transitions to the other half which is clear.
If you don’t already have a neutral density filter, but you’d like to improve the look of your photographs right now, there is a little trick you can tuck away in the recesses of your mind for the next time you’re out and about. Remember how your shutter speed and aperture are so closely related? Well, you can slow your shutter speed enough to make choppy water look smooth even without a neutral density filter by making a couple of adjustments.
Apature cheet chart link :http://static.boredpanda.com/blog/wp-content/uploads/2015/04/photography-shutter-speed-aperture-iso-cheat-sheet-chart-fotoblog-hamburg-daniel-peters.jpg