Have you ever taken photos and wondered why the exposure doesn’t seem right? Are you getting washed out skies or too dark of a foreground? One of the key tricks is to use a graduated neutral density filter (aka graduated ND’s or ND grad’s).
Camera’s are only able to capture a certain amount of dynamic range within a file. In simplistic terms, dynamic range is the amount of light captured between the highlights and shadows. Once a camera’s dynamic range is exceeded then either the whites will be blown out or the dark areas will be completely black. This is commonly known as clipping.
For example, capturing a scene with a bright sky often leads to a well exposed foreground but the sky will appear to be washed out. This is the most common scenario. The other scenario is that your subject will be too dark, e.g. a building silhouetted against a bright, correctly exposed sky.
Now as human’s we are able to see a much larger dynamic range due to how we interpret the scene and how our brains work this out for us. Camera’s are getting far more advanced, but they’re not quite there yet.
As I previously mentioned, one of the best ways to combat this issue is to use a graduated ND filter.
What is a graduated ND filter?
They are pieces of resin or glass that have a dye in the top half of the piece, this dye is neutral as to not effect the colour balance of the image. What this dye does is reduce the amount of light that is able to hit the cameras sensor during any single exposure. Filters come in varying strengths and types.
What types are there?
There are commonly three types of filter. Soft edge, hard edge and reversed graduated. These usually come in strengths of 1 stop, 2 stop and 3 stop reduction. A stop is a measurement of light and the corresponding strength will help reduce the amount of light by that much. You may see them referred to as 0.3, 0.6 and 0.9 filters and these are numbers respective of 1,2 and 3 stops.
So which do I need?
A soft edge filter is useful for mountain scenes or where something protrudes the horizon. The transition of the graduated part of the filter is gradual and fades out, this will allow you to place a filter without the effect of it being obvious on the horizon or obtruding object.
A hard edge filter is more useful for flat horizons. This is because the filters transition is abrupt and using this in a mountain scene would be obvious where the filters dark part would clip the landscape.
A reversed graduated filter is one of the most useful filters for sunrise and sunset photography. Their transition goes from light at the top to dark at the end of the transition in the middle of the filter. This is useful because where the filter is the darkest is where the brightest part of the image is.
How To Use Them:
Ideally, you would have a full set of filters to suit your style of photography but a good start up would be a 2 stop soft edge, 2 stop hard edge and a 3 stop reversed grad.
Accompanied with a slot in filter holder, you would tilt, angle and position the filter to suit your scene to bring the exposure down to a required level without the placement of the filter being obvious.
Below are two examples of the same photograph. The first photo is taken without a filter and you can see that the sky is too bright and blown out. However, the second photo was taken using a 0.9 Reversed grad filter. You can clearly see that the exposure is much better and more balanced.
Where can I get filters and what else will I need?
There are many brands of photography filters but I work with a company called 84.5mm filters.
They produce 2 sizes of filters. First off are 84.5mm filters which are Cokin P size and then there are the 100mm filters which are Lee size filters.
The 84.5mm filters are more useful for compact system cameras or DSLR’s without a super-wide angle lens.
The 100mm filters are more useful for all the above and traditional DSLR set ups.
The company works on a light, medium and strong format which equates to 1, 2 and 3 stops.
Their 84.5mm basic line filters are the entry line filters that are a cheap way of getting high quality filters. The size of them is 84.5mm (W) by 100mm (L). You can find the whole product line here
Their classic line filters are a step up. With higher optical quality these are a good step up. The size of them is 84.5mm (W) by 100mm (L). You can find the product line here
Next up is their professional line, or pro line. These are just like the classic line but are longer in length. This becomes particularly useful when you want to be super accurate in positioning of your filter. The size of them is 84.5mm (W) by 150mm (L). You can find the product line here.
Finally, there is the ultimate line and the filters I personally use. These are full size, 100mm filters and their top product. The size of them is 100mm (W) by 150mm (L). These are very useful if you already own a Lee filter system or if you own a DSLR with a super wide angle lens. You can view the whole line here
As it also happens, right now you can get offers on these filters combined with pre-ordering my book over at Indiegogo