The water level was high as we passed Bickleigh Bridge last weekend, and it seemed like a good chance to try out the variable Neutral Density filter I’d just bought. A whut? A Neutral Density filter is a filter to stick on the front of your camera’s lens that reduces the amount of light getting in. Other than that, it doesn’t change things. Colours should stay the same, no strange effects, just less light. A Variable Neutral Density can change how much light it cuts out by twisting it.
There are two good reasons you might want less light getting in to your lens:
- You have a lens with a wide maximum aperture. At a very wide setting, it can limit the depth of field, making the background really blurry. If there’s too much light, as there often is on a sunny day, your camera can’t make the shutter speed fast enough to use such a wide aperture. Add an ND filter, and you’re good.
- You want a really slow shutter speed to make action all blurry. Only really useful for making water go all fuzzy. To get a really slow shutter, you need less light getting in to the camera in the time. Add an ND filter, and you’re good.
In this case, I wanted to try making fast-moving water go fuzzy. We’ll start at 1/25th of a second, which would have been possible without the ND filter, just by closing the aperture a bit.
Not very fuzzy, but not exactly frozen in time either.
Next, half a second. Much smoother. The movement of the water has blurred so the water now looks less ‘solid’.
We can still go further, though, with the variable ND filter. Here’s a 3.2s exposure, which really does make things fuzzy. The spray starts to look a bit misty.
It would be possible to go further than this – I could push exposures up to over 30 seconds, but it these seemed like the best results. I’m not sure I like the smoother results more in this set, but it will work sometimes, and was fun to try.
The filter I bought was a Hama Vario ND, which was around £25 for the 49mm I needed for my Sony lenses. Quite a bargain, as most brands are much more, and Hama make decent filters. I bought through Amazon, as Wex were out of stock at the time, but I’d have gone to Wex otherwise.