All long exposure photography needs some way of reducing the light which is where neutral density filters come in.
Types of long exposure photography
Waterfalls - to make the water silky
Seascapes - to make the water frothy and silky
Clouds - to make the clouds streak across the sky
Removing people - to remove tourists who walk through your photo (and hope they keep walking!)
Neutral Density Filters
At first I used my circular polarizer on my waterfalls, but often this wasn't enough as it only reduces 1.5 to 2 stops and I still had to use f/22. The proper filters to use are Neutral Density Filters. These are rated by the number of stops of light that they cut out - 1, 2, 3, 6, 9, 10. So which one or ones do you buy? That was my big question last year along with, which brand was best.
The first one I bought was a 0.9 (3-stop) which was great for doing waterfalls that didn't have too much sun on the water. Then as I progressed I wanted to use them during sunsets, to get rid of people who walked through my shots and seascapes. So I bought a 1.2 (6-stop) and a 3.0 (10 stop).
|f/13, 8s, 3-Stop ND, ISO160|
Filters are expensive, there is no reason why they should be but they are and someone is making a lot of money. It might be tempting to buy them on eBay and I have and been stung. It's just not worth wasting your money - there are too many people in China selling counterfeit filters.
I did a lot of reading on ND filters as some have colour casts. I settled on the B+W 3-stop as B+W have a good reputation and you don't notice any colour cast at that low level. They have schott glass and brass rings that make it easy to get on and off your lens. The aluminium rings can be nigh impossible to get off as they stick like glue. When it came to buy my next two ND filters there was an ad on facebook about Breakthrough Photography filters who are based in California. So we did a bit of checking and eventually I bought a 6-stop and a 10-stop and also replaced my counterfeit circular poloriser. They have no colour cast and the ridges around the ring make it even easier to get on and off. I'm really glad I spent the extra to get these ones as they feel nice and are easy to use.
|f/13 4s 3-stop ND|