How to Light, Lighting Controls

How to Light: Q and A of the day – Lux answers your lighting questions

Lighting is a constantly changing sphere, with a whole host of new developments and innovations to stay on top of. To make this task a little easier we have recruited a panel of experts to help solve your lighting queries and questions.

Click in the categories below to find the questions and answers.



Connected (smart) lighting 

Using smart controls

What should I consider when retrofitting a connected lighting solution? (Ansell Lighting)

Can SME lighting companies become smart and affordable? (Aurora Lighting)

Can I incorporate smart controls into conventional lighting fixtures?  (

Why retrofit your home into a smart home?  (Ansell Lighting)

Is it possible to convert an existing lighting installation to ‘smart control’? (Nedap)


Power over Ethernet (PoE)

Is it true that PoE can do a lot more than lighting? (Igor)

Can I expand an existing PoE lighting installation? (Igor)

How does Power over Ethernet (PoE) lighting work? (Igor)

What does it look like to install PoE and who can do it? (Igor)

What are the practical benefits of PoE and what can be powered and controlled by PoE today? (Igor)

Can I install PoE at home, and what would that look like to me? (Igor)

So, what is Power over Ethernet? (Cisco)

Can you use standard RJ45 network cable with a PoE installation? (Cisco)

What electrical and data standards are applicable to a PoE lighting installations? (Cisco)

With the power rating of LED luminaires growing, what approach needs to be taken to control voltage drop along network cables? (Cisco)


Mesh Networks

How can you guarantee security with a Bluetooth mesh network? (Silvair)

Do I have to use a smartphone to control the lighting on a Bluetooth mesh network? (Silvair)

Can a Bluetooth mesh network control lighting across multiple buildings? (Silvair)

What special wiring do I need to allow for when installing a Bluetooth mesh network? (Silvair)

Do standards exist for Bluetooth connected lighting technology? (Silvair)

What do I need to build a Bluetooth mesh network? (Silvair)



What do smart sensors ‘see’? (Gooee)


Lighting controls

When will I be able to buy certified DALI-2 sensors? (DiiA)

What is DALI-2? (DiiA)

What is intra-luminaire DALI? (DiiA)

What are the differences between DMX and DALI – and does it matter? (Pharos)

How can DMX and DALI luminaires be combined in a single system? (Pharos)

What is the difference between the presence and absence detection of an occupancy sensor? (Fagerhult)

Will halogen transformers and dimmers work with LED? (LEDvance)

Lamps and light sources

Does a suitable retrofit lamp exist for G9 Halogen lamps? (Crompton)

How can I use LED to light an art gallery? (High Technology)

I’ve seen MR16 LED retrofit lamps, are LED lamps also available to replace the smaller MR11 halogen lamps? (LEDvance)

LED lamps and luminaires are commonly available in 2700K, 3000K and 4000K colour temperatures, but how do you go about choosing the correct colour? (LEDvance)

Are LED replacements available for fluorescent tubes? (LEDvance)

Emergency Lighting 

Should I invest in self-testing emergency lighting? (Ansell)

What’s the recommended light output for an emergency fitting over its lifetime? (Liteplan)

Can I ship lithium batteries by air?  (Liteplan)

How is ‘stay put’ lighting triggered? (P4 Fastel)

Do I need ‘stay put’ lighting in my premises? (P4 Fastel)

What are the compliance rules for ‘stay put’ lighting? (P4 Fastel)

Are lithium batteries safe for emergency lighting? (Liteplan)

Can an exit sign be in a warm white colour? (Liteplan)

Is it possible to convert a standard luminaire using a GLS tungsten lamp to emergency operation? (Liteplan)

Can a Power over Ethernet system support emergency lighting? (Liteplan)

What colour should the charge indicator on self-contained emergency lights be? (Liteplan)

Are Lithium Ion batteries suitable for emergency lighting? (Liteplan)

What’s a simple way to convert GU10 and T8 fittings? (Liteplan)

Why do EU emergency lights last for less time than in UK? (Liteplan)

Is there any legal requirement as to which emergency light fittings need to be maintained or non-maintained? (Liteplan)

Can dimmable LED downlights use emergency packs? (Liteplan)

What colour should the charge indicator on self-contained emergency lights be? (Liteplan)

How often should I change emergency lighting batteries? (Liteplan)

Does the top deck of a car park need emergency lighting? (

Do I need emergency lighting? (


Light Science

What is the most efficient material for LED optics? (Carclo)

What is the difference between a diffuser and a lens? (Tamlite)

When should custom optics become the standard choice? (Carclo)

Can a light fixture be effectively vibration-proof? (

Why does ‘glare factor’ matter? (Ansell)

What is the difference between footcandles and lux? (Amerlux)

What are MacAdam Ellipses and why are they important? (High Technology)

Lighting Applications 

Applications – Industrual

What is best practice for lighting high-level racking in warehouses? (Tamlite)

I need to relight an old warehouse. What should I do? (


Applications – Retail

Can I use any manufacturer’s products on a lighting track? (illuma)

Why aren’t 3 circuit lighting tracks all the same? (illuma)

How do I prepare a lighting specification for an international roll-out programme? (Amerlux)


Applications – Hospitality/leisure

How do you light a bathroom mirror? (Astro)

How do I best control the budgets for my hotel projects? (Amerlux)


Applications – Office

Are edge-lit panels aesthetically preferable to backlit panels?  (

What is the difference between edge-lit and backlit panels? (Integral)


Applications – Residential

What should I consider when retrofitting a connected lighting solution? (Ansell Lighting)

Can SME lighting companies become smart and affordable? (Aurora Lighting)

How do smart lighting systems work for the home? (Aurora Lighting)

Can I install PoE at home, and what would that look like to me? (Igor)

What are the key issues when lighting a modern kitchen?  (Ansell Lighting)

Why retrofit your home into a smart home?  (Ansell Lighting)


Applications – Outdoor

How do you light for dark skies?  (Alan Tulla, Lux Review technical editor)

What are the things to avoid when specifying step lights? (Amerlux)

What should I look for in post-top amenity lighting? (Amerlux)



Lighting in practice

How do we know an LED spec provides value for money? (

How do I specify a decent LED panel?  (

What are the regulations for installing Christmas lights?  (

How do I find a trustworthy manufacturer? (Amerlux)

How do I protect my design specification? (Amerlux)


Lighting Law

Can non-fire-rated diffusers be used in suspended ceilings in the UK? (

What is ERP regulation and does it effect me? (LEDvance)


Lighting for health and wellbeing

What is human-centric lighting? (Trilux)

What are the standards for the blue light hazard in luminaires? (

How do you measure the irradiance characteristics of UVC LEDs? (

How effective are UVC LEDs? (RayVio)

What is biodynamic lighting and should I use it? (Waldmann)

Biodynamic, circadian, human-centric lighting – isn’t it all the same thing?  (Waldmann)

What do I need to know when planning a biodynamic lighting installation?  (Waldmann)

What effect does biodynamic lighting have on the human body?  (Waldmann)