A Close Look At A Professional Neutral Density Filter System

Image by Robert Emperley

Hi and welcome to my blog. Today I am going to try to help you understand what a Neutral Density (ND) filter is. A ND filter reduces the intensity of light and colors equally, while making no changes in hue of color rendition. Simply put, a ND filter is like sunglasses for your lens; sunglasses that don’t change any colors.

There are many types of ND filters.  Some are glass, some are acrylic, and some are even digital. The digital ones are built inside of a camera. For example, in the video industry, they have had ND’s built into cameras for years. I, for one, would love to see this same technology offered to the DSLR market – it’s not like they can’t do it. Most of the “glass” ND filters are screw in type, they only fit the lenses they were made for.  Believe me when I say, glass filters can get really expensive when trying to outfit all of your lenses with ND filters. Also the glass filters do not offer a graduated fall off of filtration. This is why I choose to use a foundation system.

The foundation system I like is from a company called Formatt.  They are located in the UK, but have a big presence in the US.  Formatt makes a line of filters called Hitech, and in particular, I use the 100mm system. The system is super easy to use.  You place the filters in a foundation that fits on the front of your lens. You buy various adapter rings for your various lenses and the foundation attaches to the rings. The great thing about this system is you can stack several filters to achieve an exacting control over the ambient light.

The Hitech 100mm foundation and ND Grad on my 5D MkIII

Below is a video to show what the filters look like, and how they are used. One of the great things about the Hitech system is you can stack multiple filters in the foundation, along with an additional circular polarizer.  The rings used to secure the foundation to the lens are offered in sizes from 62mm to 95mm, so it fits almost any lens. Formatt offers other systems for smaller and larger lenses, so don’t worry if you have a 58mm filter thread size lens.

As great as the foundation is, I often just hand hold the filters against the front of the lens.  I do this so I can feather them. When I say feather them, I mean slowly, in a small circular pattern, move the filters around in front of the lens during the exposure. I am always careful, making sure not to move the camera. Remember these filters are acrylic and can scratch during normal use or if you don’t clean them carefully. So, if your filter becomes scratched, don’t throw them away, just feather them during the exposure. If the scratches are moving during the exposure they will not bee seen in the final image. With these filters, you are not limited to shooting at the golden hours, you can easily tame harsh sun and make pictures almost any time.

The main purpose for an ND filter is to take control of ambient light conditions. Lets say you want to shoot outside at f1.8 to blur the background so it looks nice and soft, but the sun is too bright so your images are over exposed. Yes, you try to use the shutter to darken the scene, but even if you have a camera that goes to 1/8000th, often, it still isn’t enough to darken the scene. So then what?  Do you just live with a blown out sky? What if you want to use flash as well, the max sync speed is 1/200th in most cases, and that speed you will never tame a bright sun. Now, what do you do? Maybe you can come back when the sun goes down… or you can grab an ND filter and get to work.

Below are three images that  I shot during the time I made the video. I hope they illustrate the importance of having a set of ND filters as part of your kit.

This image is how the desert looked with no filter.

This is the same shot with an ND Hard Edge (HE) and the ND Blender filter stacked and placed in front of the lens.

Lastly three filters stacked, the HE, An ND Graduated, and the Blender. Also a little post to pump the saturation, set a black point and a little clarity.

Now go order some ND filters and always be able to work, no matter what the sun is trying to do. I love to play with flash and overpowering the sun, but the trick to doing this effectively has always been an ND filter. Thanks for taking time to visit today. Sincerely, Thomas Shue