Polarising Filters explained

Polarising filter basics 

Polarising filters have a number of applications in photography making them very useful tools in certain situations including in photography for real estate. Like polarised sun glasses most people are aware of, these filters work in a similar fashion managing reflection and suppressing glare from reaching your eyes. In practice this means that by wearing a pair of polarised sunglasses you can avoid blinding reflections, when driving for example. Similarly in photography you are able to shoot scenes where you want to avoid any type of reflection including window shots (see below), shooting through mirrors, seascapes and more.


The above shot was taken using a polarising filter, suppressing reflected light and providing a more detailed exterior.

Polarising-Filters-2This shot was taken without the polarising filter picking up the reflected light from the interior space. This ended up in a poor composition hiding a lot of detail from the internal garden, and as a result missing the interaction between the interior and exterior areas.

Other properties of polarised filters include image darkening and thus allowing for longer exposures during bright scenes. This gives the photographer the option to blur moving subjects, take landscape or seascape shots with milky waters etc. This filter is more frequently used for landscape photography, where sceneries appear clearer sine the filter removes reflections from any particles present in the atmosphere. Additionally polarising filters render more vivid colours making a scene more appealing.


Your first purchase

Polarising filters prices can range from €20 to over €100 for premium glass. This does not mean that the lower cost filters are not good for the job, it simply means that the photography enthusiast or the professional’s demanding eye might result in a hefty purchase. A low to mid range cost filter will be more than satisfactory for the amateur’s needs.

Purchase tip: Unless you have already acquired a filter mount, a crucial factor to be aware of before your first purchase is to make sure that the lens and filter have the same size. Your lens size is found on the front rim and is represented by a symbol similar to the Greek letter Φ. So for this standard Canon 18-55mm lens a compatible polarising filter should be at 58mm.Canon 18-55 

Aperture & Depth of Field explained

Your cameras Aperture (measured in f-stops) which controls Depth of Field is one of the most important creative controls for your image composition. The human brain is designed to crunch information and by default directs the eye to the sharp (in-focus) parts of any image where information can be easily processed. In contrast out-of focus and blurred parts of an image are ignored.

Large Depth of Field

A large depth of field means that the image will be in sharp focus all the way to the background (image 1).  This image compels the viewer to look around from foreground to background and absorb all the information. 


Shallow Depth of Field

A small depth of field means that the image will be in sharp focus only where you direct it (image 2). In this case the focus is in the immediate foreground making the sparrow the subject of the image.   This composition drives the viewer directly to the subject and has a more relaxing feeling to it since your brain is required to process only a small amount of information. 



About Property Photography

Each type of photography has some elements that work you should be aware of. Conventional property photography for example requires sharp images and a large depth of field* which means that a tripod will be a necessary item in your shooting tool-kit. Tripods are essential for long exposures and in order to avoid camera shake. All professional real estate photographers will find themselves at some point shooting in enclosed spaces with high dynamic range (HDR) scenes, encountering problems including blown out highlights and metering.

Lighting is one of the most common issues you need to address as a photographer, however there are several solutions including the use of external light sources or even post processing. As you can see in the two images above, the highlights of the left image are not blown out but seem evenly metered.

*Depth of field refers to how much of the image is in focus. A large depth of field means that the image will be in sharp focus all the way to the background.

* Dynamic Range refers to the differences in light intensity of an image. A shadowy room with a bright source of light coming in from a single window can be described as a high dynamic range scene.

About Photography

Photography skill sets can be categorised under two main headings, mechanics which involves the technical knowledge required to take photos including post-processing, and composition which involves the individual’s interpretation of a specific image through the application of mechanics. It is not just a matter of buying a DSL camera, turning the auto shoot mode on and start shooting away as some may think, but actually an art form.

Mechanics & Composition

All photographers require at the least a basic grasp of camera mechanics and how different settings affect the final image. This includes knowledge on a number of photography concepts like depth of field, shutter speed, ISO, white balance, metering, dynamic range and more. Then comes the artsy part of the equation which involves composition and in general the way the photographer arranges everything in his frame.