In this article we discuss the following 5 camera lens filters:
- UV filters
- Polarising filters
- Neutral Density (ND) filters
- Variable Neutral Density filters
- Infra Red (IR) filters
What is a Camera Lens Filter?
Camera lens filters are glass elements that either screw in or slot in front of your lens and are used to alter the nature of the light passing through your lens on to the camera sensor.
Different filters are used for different reasons. Some are used to minimise the amount of light entering the lens and some are used to provide special effects.
There is much debate in today’s modern age of digital and mirror less technology whether filters are even necessary. The power of post processing software such as Adobe Lightroom and Photoshop, and advances in AI editing capability add further fuel to this debate.
Ultra Violet (UV) Filters
UV camera lens filters were designed to prevent harmful ultra violet rays from entering your camera lens and they are also purported to reduce haze.
My personal opinion is that these filters are totally redundant and a waste of money EXCEPT in one area – they can provide physical protection to the front end of your lens.
I accidentally dropped this lens on to the corner of a table. As you can see from the above picture – the UV filter shattered but the front lens element survived intact!
They are also useful in very dusty or sandy conditions when you wish to keep the front element of your lens clean. UV filters are easy to clean and you don’t particularly have to worry about being overly cautious when cleaning them.
UV filters are cheap and easy to come by so perhaps consider buying one for lens protection if nothing else.
Polarising filters reduce reflected sunlight and are useful when taking photographs that have sunlit water as part of the composition.
I find they are only useful when shooting straight down into water as well as at a low angle across the surface of a body of water. They are also used to bring a darker blue to pale skies however I seldom use them for this.
The polarising filter is nearly as redundant as a UV filter in my opinion. There are a number of tools you can use in post processing to reduce haze and improve clarity and contrast. My current favourite tool for this is the dehaze slider in the Lightroom develop module. A little of this goes a long way so be careful!
Neutral Density (ND) Filters
The above image of a ship wreck off the Skeleton Coast in Namibia was taken using a 10 stop ND filter.
A neutral density filter reduces the amount of light entering your lens and is great for blurring motion in moving water or clouds in skies. They are available in fixed densities from a 10 stop filter right down to a 3 stop filter. Each stop referenced is a stop of light.
It is sometimes impossible to slow your shutter speed sufficiently in bright light in order to achieve these effects and that is when such a filter comes in handy.
I always pack one when travelling and have them in various diameters and stop values.
Variable Neutral Density (VND) Filters
The variable neutral density filter or VND as pictured above are adjustable, usually over a range of 2 stops to 8 stops of light reduction. In essence they are marketed as an alternative to buying several individual ND filters.
They have a rotating front ring that allows you to choose the ND amount required however, I have always found them fiddly to use.
They can cost as much as USD 250 and personally I only use them when shooting video in bright conditions.
Infra Red (IR) Filters
IR filters block visible light and only allow infra red light to pass through the lens.
Use of these filters slows down the shutter speed of your camera to such an extent that you will need to use a tripod to get sharp images. The minimum shutter speed I have been able to achieve at f5.6 is 25 seconds using an infra red filter.
You can get many different types and colour effects of IR filters and my personal favourite is the 720 nm black and white IR filter. Another option is to convert an old camera body to infra red and this allows you to take IR images using your camera in a more conventional manner.
Read my article on Infrared Wildlife Photography
It is recommended that you research the types of lenses that handle IR filters best as many of the modern lenses will produce hot spots on your images. The best reference source I have found for this research is Kolari.
In my opinion the need for buying a load of different lens filters is often over stated.
That being said, landscape photographers would have an argument for the use of graduated, slot in neutral density filters and I wouldn’t begrudge them that. It does add to the overall experience and provides room for experimentation out in the field. You can read more about slot-in graduated filters here.
I have reduced my filter collection down to various sizes of IR filters and ND filters. The truth is you can usually achieve the results you are looking for either in camera or during editing.