ND filters have been a popular topic lately, so Action Photo School decided to share how we use them and what challenges we face while using them. Using ND filters for action sports sounds like a stupid idea.. doesn’t it? Why would you stop the light from hitting your sensor, when you are trying to freeze motion and get the highest shutter speed possible?
It isn’t a great idea, until you introduce a flash in the scene! Generally speaking ND filters have been popular among flash fanatics trying to overpower the sun. We’ve all seen these edgy great looking images, captured midday with a lot of flash power.
So now you’re thinking, “why not just stop down the lens?” and the answer is for shallow depth of field. Shallow depth of field is often an image characteristic of true professionals. It also helps you keep the subject separate from the surroundings.
You can always stop down the lens to f16, and get great images with a powerful enough flash, but you can’t do it so there is a pleasing bokeh behind your subject in bright midday light. That’s where ND filters come into play. You thread the filter on the front of the lens to bring the ambient exposure down. From our experience the best results are achieved when you underexpose the ambient light by 1-stop, but this is mostly a matter of taste.
Depending on the time of the day and the lighting situation you may need ND filter with a different light blocking power. They come in different varieties, ND2, ND4, ND8..ND512. The different