Sunglasses for your camera

As promised in last week’s article I’m going to look at using Neutral Density (ND) filters to enhance your images. The ND filter is basically a filter that is placed before the lens (or dropped into a filter slot) and reduces the amount of light making its way into the camera. Think of the ND filter as sunglasses for your camera. ND filters do not change the colour of the light being captured by the camera and lens, hence the ‘neutral’ in the name.

I don’t use filters too much but I find these very useful. The filters I would recommend you to start off with (apart from your Ultra Violet (UV) filter which should be on every lens), are a Graduated ND, Full ND (probably 3 would be ideal) and a Polarising filter. You can get 100s of filters but some are very gimmicky, start off with these. The two common brand names are Cokin and Lee filters. There are other filter manufacturers out there but the two mentioned here would be the most common. Buy the ‘Pro’ range as these are bigger and better and should have no colour tints when used on your images.

I would recommend you get a filter holder, which can hold three filters together and adapter rings to suit the diameter of each of your lenses. The adapter rings screw onto the front of your lens allowing you to clip on the filter holder. This means you can use your filters on every lens. (please see the illustration) The diameter of your lens is on the front beside the front element.

The Graduated ND filter I find is really useful for landscapes. When you check your meter reading for a landscape, the sky is usually brighter than the foreground. If you expose for the sky the foreground goes dark and if you expose for the foreground the sky goes lighter. This is where the graduated ND comes into its own.

Because the ND is darker at the top and gradually goes clear at the bottom you can darken the sky and not interfere with the foreground. I have two images or Carlingford Lough using this technique. No photoshop has been performed on these two images. They are ‘as shot’ in camera showing the power of the Graduated ND filter.

With the filter holder you can add as much or as little of the filter as you desire by sliding the filter to the desired position, allowing for flexibility and subjectivity as to the desired amount of darkening you wish to add to your sky.

The next filter I’m going to talk about is the Full ND. This means that it is the same level of ‘darkness’ over all the filter compared to the ‘graduated’ one. It usu

Camera with filter holder and three filters inserted, and right, Graduated Neutral Density (top) and full 3 stop ND (bottom).

ally is rated in how many ‘stops’ of light it is designed to block. The normal is 3 stops per filter but you can buy different versions. Some going up to 9 stops or more.

So why do we want to use ND filters in the first place? Basically it allows us to use really, really slow shutter speeds. If you remembers form previous pieces (Rules of Thumb) I’ve said, ‘ to show movement use a shutter speed of 1/30th of a second or slower. The shutter speeds I’ve used for the pictures illustrated were 30 seconds. You can see the effects on the moving water.

Because you are using really slow shutter speeds you need a tripod to support your camera, so it won’t move. Another tip is to use the self-timer on the camera or a remote trigger. ( You can buy remote triggers to use with all brands of cameras.) By doing this you lessen the chance that you will move the camera by pressing on the shutter release button when you make the picture. By using these two tips the ‘moving part’ of the image, in this case the water will be blurred but the ‘still items’ such as the trees and stones etc., will remain sharp.

I’ve photographed two local areas so you can get out and try this for yourself. The first was Carlingford Lough and the second was the small waterfall/stream

in Ravensdale Forest Park. It’s great fun and can pass quite a lot of time.

When you photograph moving water you get this really atmospheric effect like mist or as in my images, like the water has changed into some type of plastic draped over the rocks so it can totally change you landscape. Again, I use it sparingly because like most things in life when you see something over and over again it is not as surprising and becomes commonplace.

Another addition to ND filters, to make your shutter speed really slow is to reduce your ISO. Remember from my previous tips, ISO is how sensitive the imager in your camera is to light. So to make it very sensitive to light use higher ISOs such as 1600, 3200 etc (remember this gives you noise or grain in your images, so be careful) or vice versa go to a lower ISO such as 200, 100 or even lower, if your camera will allow you. By doing this you will be able to achieve very low shutter speeds even on a bright day.

I hope you really enjoy trying out these techniques. So ‘ til next time, enjoy your camera and more importantly than ever, stay safe!

This is a 30 second exposure with Neutral Density Filters used. This is another 30 second exposure using three Neutral Density filters.

No graduated ND.

This is the same picture as before with the addition of a graduated Neutral Density filter darkening the sky. It is the same exposure as the first image, but you can see clearly how it gives more detail in the clouds..