Using filters can make a huge difference to your photography and is one of the key skills to learn when improving your photographic technique. But with so many choices on the market it’s difficult to know where to begin! This handy guide is designed to help you to understand how filters work and why you should be using them.
In basic terms, a filter is an accessory that is attached to the front element of your lens to change the light that is entering your camera. There are many ways in which the light can be changed by filtering, such as colour, contrast and the amount of light that is coming through. For example, a Neutral Density filter (or ND Filter) will cut out a lot of the light that is coming through, allowing for longer exposure times (slower shutter speeds).
Filters also act as a protective covering for your expensive lenses and many photographers will have a UV Filter (which cuts out UV Light and has little effect on most images) permanently attached to their lenses. If a lens is dropped, the filter should take the damage and is much cheaper to replace than a lens.
For the majority of time, filters are used as a creative tool that give photographers a myriad of options when it comes to image making. They can be used to hold back the exposure over a bright sky, they can be used to saturate colours in a landscape image, they can be used to slow down an exposure to create a milky effect in clouds or water, or they could be used to remove unwanted reflections. Filters can also be “stacked” where one filter will work in conjunction with another to give even more options.
TYPES OF FILTERS
There are many types of filters available, but the options below are my recommendations for essential filters that every photographer should have in their kit bag.
UV FILTERS – These filters cut out UV light and reduce haze in photographs. For the most part, UV filters are used as a protective filter that are permanently attached to the lens.
NEUTRAL DENSITY FILTERS (ND Filters) – ND Filters are used to reduce the amount of light entering the lens, which allows for longer shutter speeds and narrower apertures in bright conditions. This can help a photographer to produce long exposures where movement is recorded in an image. ND Filters are available in a range of strengths for greater effects. An ND filter with a bigger number will block out more light, allowing for longer shutter speeds. A 10 STOP FILTER (for example the LEE Filters BIG STOPPER) changes the amount of light entering the lens by 10 F Stops. This allows for very long shutter speeds and is a popular tool amongst landscape photographers.
NEUTRAL DENSITY GRADUATED FILTERS (ND Grads) – ND Grads are used in the same way as ND Filters, with the difference being that the effect is graduated over a portion of the scene. For example, a scene with a bright sky and dark foreground would benefit from the use of an ND Grad in order to hold back the light in the brighter (sky) area of the frame. If the foreground was correctly exposed, without the use of an ND Grad the sky would be overexposed. ND Grads also come in varying degrees of strength for greater or lesser effects and are available as HARD or SOFT. The Hard or SOFT refers to the transition or graduation of the filters effect. For example, a HARD Graduated filter is perfect for using over a very definite horizon, such as an open sea with a straight line. A SOFT grad would be the best choice for a mountainous scene, where the effect can be blended in to suit the landscape.
POLARISING FILTERS – A polarising filter is an essential tool for photography and will become an indispensable piece of your kit. Polarising Filters are great for cutting out unwanted reflections on surfaces such as water or glass and will also richly enhance your colours (particularly blue skies). To use a polarising filter, simply turn the filter to give a stronger effect.
A polarising filter will absorb 2 stops of light so it is important to keep an eye on your shutter speed when using your polariser. The reduction in light entering the lens can prove useful when trying to slow down a shutter for creative effects.
Filters all work in the same way, but can be attached to your lens using different methods, the most popular being “screw in” and “slot in.”
Screw In filters attach to your lens by threading onto the front element. It is important to note that different lenses have different filter thread sizes. For example, the Canon 18-55mm kit lens thread size is 52mm while the 24-70mm F 2.8L thread size is 82mm. Screw in filters need to be attached to the corresponding lens thread size. You can usually find your lens thread size on the front element of the lens ( a number marked with mm i.e 52mm).
Slot In filters are connected to your camera lens using filter holding kit with slots for the filters to go into. You will also require an adapter ring which will allow you to attach your filter holder to your lens, again you must use the correct thread size which you can find on the front of your lens. There are many different manufactures offering filter systems. You should stick with one manufacturers system to ensure that your filters will work as desired.
Professionals generally prefer to use Slot In Filters, with the LEE system being the benchmark in quality, although very expensive when compared to the alternatives.
Please remember that the cheaper filters may degrade image quality and may not yield the best results, it does seem silly to purchase an expensive lens capable of producing great photographs, only to attach a cheap filter to the front!
All of the above filters are highly recommended and will set you well on your way with filtering, however that does not mean that you should go out and spend lots of money immediately. In my opinion, it is better to build a solid set of decent filters over time, rather than buying lots of cheap alternatives that will give poor results.
SCREW IN – Look for brands such as HOYA who have a great reputation within the industry and have been producing high quality screw in filters for many years.
SLOT IN – The ultimate system is the LEE Filter kit, however it does come at a cost. I would always advise the keen amateur to invest in the LEE system providing that they are confident that they will get the use out of them. By this I mean that you should be purchasing this level of filter only when you are shooting outdoors on a regular basis. They are the best filters available on the market and the choice of many professionals. There are cheaper alternative slot in filters such as the Coking P Series system which will give good results for a fraction of the cost of the LEE System and should be considered.
In my opinion, the slot in system is superior to the screw in system and offers a more flexible way of filtering your photographs quickly and effectively.
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