How Perforated Panels Influence What You See

Influencing Colour Perception

Perforated panels will influence the perception of colours behind them.  As light passes through the open parts of the panel or reflects off the panel itself, it can alter the way colours appear. Depending on the pattern used, the angle of the panel in relation to the sun, and the colour of the powder coat finish, the visual perception of colour will change.  Think of it as the panel adding a filter overtop of the colour behind.

This happens because the pattern and powdercoat colour choice subtly alters the hues of light that reach the surface behind them.  Colours reflect different wavelengths, absorbing the rest, and as this happens the reflected light will impact the perception of colour any anything it lands on.  So even though perforated aluminium is obviously not transparent, the reflected light will be affected enough as to change the perception of any colour it shines on.  Altering the size and spacing of perforations will then change the visible colour hues further.  

Influencing Privacy Levels 

The choice of screen colour can also influence privacy levels.  Lighter colours will make the screen appear to be more solid and will reduce the extent to which it’s possible to ‘look behind’ the perforated screen.  

What’s happening is the reflected light from the panels is brighter than the light behind them, effectively drowning out whatever might be otherwise viewable.  It’s the same as trying to look into a dark room from the bright outdoors.  The reflected light from the window will obscure whatever is in the room, making it hard to discern shapes and colours in it.  

Of course, the flip side is also true.  If the building behind the facade is lighted, then that light will shine through the perforated panels and seemingly increase what it's possible to see.  It’s really the same as the net curtains that became increasingly popular in Victorian England, lasting well into the 1980s.  Almost unfailingly made in bright white (at least until they generally withered to a tobacco stained yellow) they worked by reflecting sunlight to obscure what went on behind closed doors.  Occupants concerned with their privacy would still have normal curtains or blinds though, knowing that at nighttime the dark suburban streets would eagerly absorb the light inside the home and passers-by could see more of what was going on inside. 

Of course, there are other factors influencing what can be seen through a perforated panel when looking from the outside, the most obvious being the open area.  Reducing the open area generally tends to reduce visibility and increasing it…well, that increases visibility.  

Open rate should not be confused with hole size (aperture).  Smaller holes can allow near perfect visibility if there’s enough of them.  And smaller holes at closer centres are less effective at screening than larger holes at wide centres, even if both patterns have the same open area percentage.  

Another important consideration affecting privacy is proximity between the viewer and the perforated pattern.  Generally speaking, the greater the distance between the eye and a perforated panel, the less can be seen through it.  For building occupants, the opposite is true and the facade becomes a sort of giant pair of stenopeic glasses, blocking direct sun for shading but affording a relatively uninhibited view of the outdoors.  

Using Perforated Panels to create a Picture

We’ve concentrated on the smaller, less obvious ways perforated panels can influence what you see so far.  Yet we should also mention how perforated panels have the ability to create relatively detailed pictures.  

By cleverly using different open rates, it’s possible for the perforated panels to take the form of a picture. It’s important to take background lighting and viewing distance into account when designing the image, with a positive image relying on a dark background, whereas an inverted image requires the use of artificial lighting from behind.  

For the size of the holes, the design needs to establish where the optimum viewing position will be.  For example, creating a picture with perforated panels for passers-by needs to factor in the distance between any walkway and the panels themselves.  

Examples of Perforated Panels

We’ve worked on various projects where perforated panels have been used to create a unique aesthetic, offer privacy or shading.  The following have been selected to highlight different types of panels but if you’d like to view more, please visit the case studies page.  

Les Mills Car Park

A unique 3 dimensional profile twinkles after dark as the lights from the car park shine through the custom made panels with diamond shaped holes.

Alexandra Park Stage 2

The façade screen is formed from 3mm aluminium sheets finished with a white powder coating. The custom dapple pattern is made up of random rectangle perforations that are backlit to display a light show that slowly evolves through the night.

Ormiston Town Centre

A custom variation of the dapple ‘lightshade’ pattern carefully follows the contours of the parking ramp and powder coated in that burnt orange, the dappled light accentuates the entrance and exitway as it snakes its way from inside to outside. 

Te Kura o Manunui

White perforated screens featuring a standard dapple Hexagonal perforated pattern, contrast against the dark coloured brickwork behind and provide shading for teachers and students. 

Windy Ridge School

A custom dapple design uses different open rates to cleverly portray depth, creating a scene that changes, depending on your viewing angle and the time of day.

Mairangi Bay Pump Station

The perforated screens show two local Pohutukawa trees, twinning the real greenery sitting behind the pump station. 

If you’d like to learn more about perforated panels or discuss options for your project, please contact us.  We’d be happy to help.