Luminance Contrast-dev2

Luminance contrast is defined in Australian Standard 1428.1-2009 as ‘the light reflected from one surface or component, compared to the light reflected from another surface or component’, however this is commonly misinterpreted as a colour contrast. The surface brightness is measured by its luminous reflectance. Luminance Contrast is a measure of the difference in brightness of two surfaces, resulting in a Luminance Reflectance Value (LRV). Once the (LRV) is identified for each surface or component, you are able to calculate the Luminance Contrast between the two.

Luminance Contrast in Wayfinding applies to:

General Signage
Braille Tactile Signs
Visual Indicators on Glazing
Doorways
Tactile Ground Surface Indicators
Stair Nosings
Toilet Seats
Pathways
Shorelines
& more !

Why Is Luminance Contrast Important?

Luminance Contrast plays a pivotal role in Wayfinding, serving as a crucial element in enhancing visual perception and ensuring public safety. Contrast, by definition, enables the distinct separation of objects from their background, facilitating our ability to detect and recognize elements within a space. Moreover, it plays a significant role in depth perception, aiding all individuals in accurately gauging distances between objects and destinations. How useful is a sign if no one notices that it is there?Luminance Contrast is particularly vital for individuals who have low vision levels . For Wayfinding, it becomes an indispensable tool, providing essential visual cues that contribute to a more accessible and navigable environment. Individuals with low vision levels can identify that there is a Braille Tactile Sign on which they can read the Braille & Tactile Elements with their fingers to determine the direction that they need to travel in to reach their destination. By complying with Luminance contrast Requirements in Wayfinding Design, you not only enhance the overall user experience but also contribute to inclusivity, ensuring that people of all abilities, can navigate spaces with confidence, independence and dignity.

Luminance Contrast Requirements for Braille Tactile Signs

A minimum of 30% Luminance Contrast is required between the tactile graphics & the sign face, as well as the sign face on the surface it is mounted to; as per Standards Australia AS1428.1 & AS1428.4.1, a.

Building Codes of Australia - Luminance Contrast

BCA D3.6 (4) Luminance Contrast

4. Luminance Contrast

The background, negative space, fill of a sign or border with a minimum width of 5mm must have a luminance contrast with the surface on which it is mounted of not less than 30%.
Tactile characters, icons and symbols must have a minimum luminance contrast of 30% to the surface on which the characters are mounted.
Luminance contrasts must be met under the lighting conditions in which the sign is to be located.

5. Lighting

Braille and tactile signs must be illuminated to ensure luminance contrast requirements are met at all times during which the sign is required to be read.

Read the National Construction Code Here.

Need help with the Luminance Contrasts for your project?

Still not sure if your colours meet the required LVR? Our Experienced Team of Wayfinding Specialists & Design Consultants are here to assist you in determining the Luminance Reflectance Values (LRV) for your chosen color palette. BTS Aust. have portable colour matching equipment that can scan and colour match surfaces (paint, plastic, wood, paper, cardboard, concrete, some fabrics and powders) so that we may determine the Luminance Values. If LVR has not been reached, we will work with you to find a solution that stays on brand, elevates your design and meets regulations. Simply give us a Call and ask our Friendly Team for their advice.

Disclaimer: It is the responsibility of the client to ensure a compliant luminance contrast is reached between the sign face and the surface it is mounted to. The environment in which the BTS are mounted will vary from project to project and other factors may change after consultation – eg: the lighting conditions in which the sign is to be located.

Luminance Reflectance Calculator

This calculator can be used to calculate the Luminance Reflectance Value (LRV) between two colours / elements, to obtain the Luminance Contrast percentage. To use this easy LRV calculator, you will require the LRV for each element you are comparing.

LVR Calculator (Bowman-Sapolinski)

In line with Part B4 of AS 1428.1 (2009) and Part E3 / E5 of AS/NZ 1428.4.1 (2009), the Bowman-Sapolinski Equation is used to calculate the LRV readings. The equation used for calculation is:

- C = 125 (Y2 − Y1)/(Y1 + Y2 + 25).
- C is equal to the calculated contrast.
- Y1 and Y2 refer to the luminous reflectance values (LRV) of the two surfaces to be calculated.
- Y1 is to be darker than or equal to Y2.