Outdoor Lighting Guide

Lumena Lights offer an amazing selection of outdoor lighting of all types, one of the UK’s largest ranges. We specialise in 4 core areas: Professional Solar Lights, including Solar Street Lights,  Bollard Lighting, Dusk to Dawn Lights (photocell) and 12V Garden Lighting.

Within our professional solar range are high output, solar street lights, solar wall lights, solar bollards and path lights and solar flood lights, all of which have up to a 5 year guarantee. We stock many exclusive illuminated bollard designs, in a variety of colours and heights, suitable for all applications, whether it be an intimate garden area or large commercial premises. Some designs are also available with in-built dusk to dawn sensors, alongside our dusk to dawn / PIR motion sensor security wall lights. We stock and supply many styles of outdoor lighting in both 12v and 240v:









Materials for Outdoor Lighting

Durable materials and reliability are of the utmost importance when it comes to outdoor lighting. Luminaires should be designed to withstand he elements and last for multiple years. They should also dissipate heat to prevent overheating of fittings. Lumena offer at least a 2 year guarantee as standard on most garden lighting designs.

Finishes of Outdoor Lighting

When it comes to finish, one practice is for the light source to blend in with surroundings at night, with the effect of being the main attraction. During daytime, if the light fittings will be in view, it is important that they look the part too, almost as their own feature. Lumena have created the perfect balance with attractive finishes to either blend in or stand out accordingly.

IP Ratings

An IP “Ingress Protection” Rating is a measurement of how well an outdoor light fittings is protected against specific conditions, namely water and dust. IP Ratings include 2 numbers. The first number refers to the level of protection again solid objects, such as hands, grit and dust, whilst the second number refers to the protection level against water. The protection is numerically rated from 0-6 for solids and 0-8 for liquids, zero being the lowest level of protection. The highest rating available is IP68 which means that the fitting is completely protected from solids and liquids and can be fully submerged.  All outdoor lights must have an IP Rating, ideally of IP43 or higher.

The table below describes exactly what each level of protection represents.

IK Ratings

The IK Rating of a product refers to its level of protection against mechanical impacts. IK ratings are the standard for measuring the toughness of a product. The rating is given as a number, usually ranging from IK01 to IK10, with IK10 being the highest level of protection.

IK01 indicates minimal protection against impacts, while IK10 means that the product is highly resistant to impacts. Higher IK ratings mean that a product can withstand more severe impacts and is less likely to break or become damaged.

When selecting outdoor lighting fixtures, it’s important to consider the environment in which they will be installed. If the fixtures will be located in an area that is prone to vandalism or accidental damage, a higher IK rating may be necessary to ensure the longevity of the fitting.

Voltage, in simple terms, is the pressure at which current is pushed through a circuit. Both 220-240V (240V mains) and 12V (low voltage) have their benefits, each for different reasons. The decision to use 240V or 12V should be determined by various external factors.

Mains 220-240V

Mains (220-240V) is a trusted, well known power source used since the 20th Century. The obvious benefit is that the majority of buildings are supplied with mains electric as standard, so it is easy to add onto the circuits. Cable runs can be a lot longer than 12v low voltage cable solutions, making it a great solution for larger areas. The downside is that mains isn’t a great performer in damp conditions; susceptible to tripping should moisture enter the connection / fittings. For the purpose of safety, mains cable must be armoured, or inside armoured conduit, which often results in the digging of trenches at approximately 0.5m depth. In the U.K., under Part P of the Building Regulations, any notifiable mains electrical work, such as wiring a new circuit, must be completed by a certified electrician and a certificate obtained. 

12V Low Voltage

Low voltage lighting systems (often referred to as extra low voltage in Europe) have many benefits. Firstly, 12v outdoor lights are particularly suited to outdoor environments because they withstand damp conditions without performance being affected. They’re also very safe to use, not dangerous should they become damaged, and easy for anybody to install. Plug & play installs are the easiest systems to use with no hard wiring required (see our Versa Range). The only real disadvantage of low voltage lighting is possible voltage drop (see below). By keeping cable runs as short as possible, the affects of voltage drop can easily be avoided, resulting in a safe, reliable outdoor lighting system. 

What is voltage drop?

The term ‘Voltage Drop’ relates to the amount of voltage loss that occurs through all or part of a circuit. This is a result of increased resistance which is a measure of the opposition to current flow in a circuit, measured in ohms (Ω). Electrical cables of any size and length carrying current always present resistance. Although it can affect the entire circuit, it is first apparent at the end of a cable run. A simple comparison would be a garden hose, where the pressure of water running through it reduces the further away it is from its source.

What causes voltage drop?

The 4 main factors which contribute to voltage drop are cable length, wire temperature, wire material and the cross sectional area. Generally, 12V lighting systems can withstand a maximum voltage drop of up to 8% (1V) with no noticeable effects, on the basis that the correct cable / power source is used and it is within range of the LED lamp voltage. If significant voltage drop does occur, it can cause dim lighting, strobing or no power at all.

How to reduce voltage drop

To reduce the risk of voltage drop, consider the following:

  • Reduce cable runs – keep length to a minimum with no more than 12 fittings per circuit
  • Highly conductive wire, e.g. copper. A tinned end can improve performance and longevity
  • Use high quality, heat resistant rubber cable. Minimum H05RN-F
  • Use thicker cable where possible (1.5mm² / 2.5mm²) with a secure, watertight connection

For a larger garden where this is not possible, consider laying a mains power feed to various points / areas where additional 12V transformers can be installed to create separate, smaller circuits. 240V fittings can also be connected to the mains feed if required.

Voltage drop cable run guides

Suggested maximum cable run includes cable supplied with each fitting, adaptors and connector cables. Where longer cable runs are required, use thicker cable such as 1.5mm² / 2.5mm² which have a lower resistance and reduce voltage drop. Cable runs can be increased by up to 50% (approx.) when thicker cable is used.

For longer cable runs, thicker cable is recommended. The below table is for 1.5mm and 2.5mm 2 core cable.

The above tables are a guide only. We strongly recommend that the voltage is checked with a volt meter at each fitting prior to final placement. Some external factors can affect performance, such as placement of cable etc.

Colour Temperature

Measured in kelvins, colour temperature refers to the tone of white light emitted. Most lamps on the market range between 2700K and 6500K. Warmer tones (<4200K) are typically less disruptive to wildlife than bluer tones.

       Difference in colour temperature

Beam Angle

The beam angle of an LED is important when it comes to different lighting effects. Wider beams create a floodlighting effect, suited for wall washing and larger structures. Narrow beam angles are more concentrated and create more dramatic effects, especially for more narrow focal points such as statues. It’s also important to consider the fixture housing the LED lamp, as well as any additional elements such as glare shields or lenses, as they can affect the natural beam angle.

Light Intensity (Lumens vs Watts)

Wattage and lumens coincide with one another but actually measure completely different things. Wattage is the power consumption of each lamp, whereas lumens is the measurement of brightness (intensity). Often it is believed that the higher the wattage, the brighter the lamp. Although this is sometimes the case, it is the lumens which need to be considered. For example, a low quality 5W LED may only be 330lm but a higher quality 3W LED may also be 300lm. The 3W actually uses less power (less running cost) but produces the same output as the 5W. LEDs which produce 100lm/W or more are considered the best option. It is important not to use excessive lighting so always consider what it is you’re illuminating and with what effect before finalising the LED choice. For many lighting effects, “less is more”.

CRI – Colour Rendering Index

A colour rendering index is determines how accurate a light source is when it comes to replicating colours in comparison to natural light. This is measured in Ra and generally given a value of between 50Ra and 95Ra when it comes to LED Lighting. For outdoor lighting installations, a CRI of up to 70Ra is an acceptable value, up to 80Ra very good and up to 90Ra being excellent and more suited to specialist, high end installs such as retail.


DOWNLIGHTING Ornamental / Task

A pool of light in a downward direction from a structure to another surface or feature below. Most effective on items facing upwards. Compliments other lighting techniques. Often created with hanging lights and spot lights.


The reverse effect of a downlight – illuminating from below, directed at the surface / object, away from view point. Often created with spike lights and in ground lights.

GRAZING Ornamental

The illumination of a textured surface from an acute angle. Most commonly created from uplighting but can also be created from downlights. This is similar effect to wall washing but the lights are placed at an acute angle from a ground position. This will cast a strong shadow and emphasize the texture of the surface. 


Low level lighting located in the upper section of a tree, creating shading of the branches below on the ground, bringing the grass / planting below into the feature.

MIRRORING Ornamental

The use of accent lighting on the far side of water to create a reflection visible from a main viewing point as a mirror image on the rippling water. The type of luminaire used will depend on the size of the feature to be reflected.


The use of directional luminaires to illuminate focal points such as trees, plants and statues. The difference being accent lighting is positioned closer and spotlighting further away. Common spotlights used for accent lighting and spotlighting are adjustable spike lights, downlights, in ground lights and wall mounted spotlights.

WASHING Ornamental

A wide beam covering a larger surface. Often used for wall washing, as well as washing hedges as a backdrop. Washing emphasises colour and creates atmosphere rather than accentuating texture (see grazing). Create from luminaires with wide beam angles e.g. floodlight, located below or above the featured surface. Coloured floodlights can make for some beautiful effects in a walled garden or patio area. To create an even coverage the lights must be mounted some distance from the wall itself.


Illumination of steps for safe navigation. Often from the side with a downward projection (no glare) e.g. Eyelid, or if not possible, recessed into the steps themselves. The same Eyelid designs are great for protecting a vista (distant view).


The illumination of a surface (background) behind an object to create a full silhouette of the featured object. Spike mounted spotlights and floodlights are the best luminaires to use for silhouetting.


SPREADLIGHTING Ornamental / Access

Low level, glare free illumination to create a round pool of light below. Designed for lighting pathways, steps and areas of low planting. Spreadlights are usually mushroom or pagoda shaped lights mounted on a single column. The light source is hidden under the mushroom top which distinguishes it from other Path or Bollard lights.


To illuminate behind and to the side of an object, without a background surface. This creates a more subtle halo of light rather than a silhouette.

SHADOWING Ornamental

The illumination of an object / focal point from the front, projecting its shadow onto a wall / surface directly behind. This way a small plant or tree can be made to look much bigger. The best lights for this purpose are adjustable spike or surface mount spotlights.


A beam of light travelling across the front of an object, such as a statue, fountain or tree, created by placing the luminaire to the side. Great for creating texture. If some of the object is lost in shadow, a second, slightly less bright luminaire can be installed on the opposite side to infill the shadowed areas. The light source can be an adjustable spike mount spotlight, or wall/surface mount spotlight.


Generally, underwater lighting is used to illuminate a fountain or waterfall from within the water below, or from the edge of the water feature. To create a shimmering effect, the underwater spotlight should be placed where the water is disturbed by a waterfall or spray.

Area Lighting & Floodlighting Amenity / Security / Task

General illumination of an area to enable full functionality and access e.g. safe navigation of a patio, eating areas etc. Download projection recommended.

We understand that lighting can be confusing, especially when jargon is used. Therefore, we have put together a list of common terms used in the outdoor lighting industry to try and keep things as simple as possible. Simply click the term to expand the explanation.


A popular term for the electric lamp, derived from the bulb-shaped glass envelope in which lamps are often enclosed.

The burning position defines the position in which lamps should be installed and operated and are sometimes defined by code letters as follows:-

  • h = vertical (base upwards)
  • s = vertical (base downwards)
  • p = horizontal

The candela (cd) is a standard measure of luminous intensity to allow direct comparison of the “brightness” of different light sources. For any physicists who may be reading this:-

“The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 1012 Hertz and that has a radiant intensity in that direction of 1/683 Watt per steradian.”

Bayonet (BC/B22) cap and
Edison Screw (ES/E27) cap

The electrical connection and mechanical fixing for a lamp is often referred to either as a cap or base. Lamps use a wide variety of fittings, partly to meet the appropriate electrical and safety requirements and partly to ensure that luminaires can only accept the appropriate lamp (eg to prevent using low voltage lamps in mains fittings). Common caps for standard incandescent lamps include the ubiquitous 22mm “bayonet” fitting (otherwise known as “B22d” or “BC”) and the Edison Screw (or “ES”) fitting, named after the early pioneer in electric lamp development. To ensure compatibility between different manufacturers’ products, international standards for lamp bases have been agreed by the IEC under the IEC 60061 standard. For further information see the caps and bases page.

The colour temperature of a lamp is a measure of the “warmth” or “coldness” of the light that it produces. Lamps that produce a “warm” or “yellowish” light (for example the sodium lamps used for street lighting which appear orange) have a low colour temperature. Lamps producing a pure white or bluish tinged light have a higher colour temperature.

Colour temperature is measured in degrees Kelvin (K) and is defined as “the temperature of a black body having the same colour appearance as the type of lamp being considered”.

  • Lamps with a colour temperature of less than 3500K are usually described as having a “warm” appearance
  • Lamps with a colour temperature between 3500 and 5000K are considered to have a “cool” appearance,
  • Lamps having a colour temperature over 5000K are said to have a “cold” appearance.

Typical colour temperatures are:-

  • High pressure sodium lamps: 2000K to 2200K
  • Tungsten filament light bulb: 2700K
  • Tungsten halogen lamps: 3000K
  • Fluorescent lamps: 2700K to 6500K
  • Metal halide lamps: 3000K – 5600K
  • Daylight: 5500 – 6500K
  • LED bulbs 3000K-6500K

The word “dichroic” literally means “two coloured”.

Lumena stock dichroic lenses which often appear to have a different colour around the edge. This is due to refraction of light. Visible light is reflected forwards whilst the heat is transmitted backwards

The filament is the part of an incandescent lamp that glows as an electrical current is passed through it. In very early lamps the filament was made of carbon, before changing to tungsten filaments. Many LED lamps now have the appearance of a filament, but instead of the filament heating up as per traditional lamps, the filament is actually a metal strip lined with LEDs.

Fluorescent lamps are a type of gas discharge lamp which generate invisible ultra-violet radiation and then use a phosphor coating on the inside of the lamp glass to convert this into visible light using a process known as “fluorescence”. By using different coating materials, fluorescent lamps can be made to generate light in a range of different colour temperatures. Typically these include Warm White, White, Cool White and Daylight versions.

The tube diameter is often expressed in eighths of an inch (e.g. T5 = 5/8” = 16 mm).

Advantages of fluorescent tubes include:-

  • High energy efficiency
  • Long operating life (typically over 10,000 hrs)
  • Even light distribution.

Some fluorescent lamps are manufactured without the fluorescent coating and use a bluish black glass in order to deliberately emit only light in the ultra-violet (UV) spectrum. These are used for specialist applications such as banknote forgery detectors and nightclub special effects lighting.

Fluorescent lamps are generally designed to work directly from the mains (110 or 240V AC power) but require a starter and ballast or electronic gear to operate. Electronic control gear (ECG) converts mains power to a very much higher frequency and gives several advantages over conventional ballasts and starters including:-

  • Greater efficiency and hence lower power consumption.
  • Reduced flickering
  • Faster starting

Usually manufactured in a tube shape, fluorescent lamps can also be found in circular, “U”-shaped and a variety of other specialist shapes.

Halogen capsule lamp and Tungsten halogen capsule encapsulated in a glass outer bulb.

Tungsten halogen lamps are similar to incandescent lamps but instead of just being filled with inert gas they also have small quantities of halogens (bromine, chlorine and iodine) or their compounds added to the filler gas and use quartz instead of glass for the lamp capsule. Benefits of tungsten halogen lamps include:-

  • A slightly higher colour temperature than ordinary tungsten incandescent lamps, giving a bright, white light, ideal for shop display lighting.
  • Physically much smaller than equivalent tungsten incandescent lamps.
  • Longer rated life – typically 2000 to 5000 hours or more.

One disadvantage of tungsten halogen lamps is that the quartz envelope is much more sensitive to contamination than ordinary glass bulbs. The quartz capsule must not be touched with bare hands since contamination can lead to overheating and severely reduced life. Some designs get around this by encapsulating the lamp inside a glass envelope.

The International Electrotechnical Commission (http://www.iec.ch/) is the authoritative worldwide body responsible for developing consensus global standards in the electrotechnical field. IEC is dedicated to the harmonization and voluntary adoption of these standards, supporting the transfer of electrotechnology, assisting certification and promoting international trade.

Lamp is the generic term for a light source. LED light bulbs, tubes, capsules, sodium, corn and spots are all types of lamp. 

LED stands for Light Emitting Diode. LED’s are now widely used in the latest lamp technology. Typically emitting as much as 10 times the light per watt as a Halogen Bulb. Efficient LEDs have efficiencies of at least 100 lumens per watt with the most efficient reach 200 lumens per watt. LED is the best low energy light source available. LED lamps life can vary from 10,000 hours up to 30,000. Previously up to 50,000 hours was quoted but that is now regarded as optimistic.

Lumens (lm) is the standard unit of measurement used to measure the total light energy emitted by a source, based on the Candela. Often used to describe the brightness. The rule to remember is the higher the lumen output, the brighter the light will be.

Luminaire is the general term for the fitting into which a lamp is installed. This will always include a lamp holder with the electrical connection to the lamp and may also include shades, reflectors or diffusers along with decorative, protective and/or safety features.

Luminous Flux is the measurement of visible light emitted from a unit over wavelengths visible to the human eye, used to describe the brightness of light emitted from a source. Often confused with Radiant Flux, it is important to understand the difference of the two. Luminous flux is adjusted (weighted) to the sensitivity of the human eye, whereas radiant flux measures the total power of all light emitted and is not adjusted. Luminous efficacy is the ratio of total luminous flux to radiant flux.

Metal halide lamps are a type of discharge lamp that creates an electrical arc inside a high-pressure gas capsule containing various rare earth compounds. Usually used in retail, showroom and factory applications, they can create a very crisp white light with colour temperatures ranging from 3000 to 10,000°K.

Many spot and flood lamps are manufactured using a thin film of reflective aluminium deposited on the inside of the glass. Unlike dichroic reflectors, this reflects both light and heat forwards out of the lamp.

A transformer, also referred to as a driver is an electrical device which transfers electric energy from one circuit to another, either by stepping up (increasing) or stepping down (decreasing) the voltage. Lumena 12v transformers reduce 240v AC to 12v AC.

The term ‘Voltage Drop’ relates to the amount of voltage loss that occurs through all or part of a circuit. This is a result of increased resistance which is a measure of the opposition to current flow in a circuit, measured in ohms (Ω). Electrical cables of any size and length carrying current always present resistance. Although it can affect the entire circuit, it is first apparent at the end of a cable run. A simple comparison would be a garden hose, where the pressure of water running through it reduces the further away it is from its source.

For more information on voltage drop, click here.

Named after James Watt, the inventor of the steam engine, the Watt (W) is a standard international unit of measurement of power. In the case of electric lamps, the “wattage” of the lamp defines the amount of electrical power that it consumes and also is related to the brightness of the lamp. However since different types of lamp are more or less efficient in converting electrical power into light, the Watt is not in itself a measure of brightness. For example, a 5W LED lamp is approximately as bright as a 50W CFL yet it consumes only one tenth of the power.

When it comes to outdoor lighting, it is really important to have the correct balance where we have adequate lighting with minimal impact to the environment. The main areas affected by excessive light pollution are astronomy, wildlife, plants, and of course climate change.

At night, it is important that areas are effectively lit to enable us to move about safely; however, this is often overdone creating a “runway effect” which can be damaging to the environment. Firstly, consider how much light is actually required to illuminate the desired area. This will determine the design of the light, as well as the output and colour temperature.

Light pollution is created by luminaires projecting light into the night sky (upward light). The amount of upward light produced by a luminaire is due to the overall design of the light. Luminaires with glare shields and downward projection greatly reduce light pollution.

When it comes to brightness, people often over-estimate what lumens output is actually required. When asked which bulb a customer requires, it is not uncommon for their response to be “the brightest option”. Although many would believe a more intense light would be better to achieve maximum visibility, sometimes it can have the opposite effect due to dazzling contrast. Eyes adapt better when the light emitted from the luminaire is harmonious with the surrounding, ambient luminosity.

Naturally, warmer colour temperatures have less of an effect on surrounding wildlife, and reduces star-warping. For example, bats are less effected by a red hue of light, creating orange/yellow tones opposed to very cold, daylight white and green which are higher up the spectrum. Blue light has the most negative effect when it comes to light pollution so should be kept to a minimum. Sticking to colour temperatures of 3000K and less is the ideal solution, often referred to as “bat-friendly”.

In addition to the amount of light required, the illumination timespan is also an important factor. Lighting up a specific area all night long is not always necessary. As well as manually turning off luminaires towards the later evening, automation is a handy solution. Luminaire illumination times can be controlled by way of timers or sensors such as motion sensors.

To reduce your energy consumption and global warming further, professional solar lighting is a great alternative. Technology has greatly evolved over recent years make it more reliable and long lasting without the need for electricity. They often emit a lower level light; enough to fulfil the task at hand but without taking president over wildlife habitat. In-built gradual dimming sequences further reduce light output during hours when additional illumination is not essential.

Need More Help?

If you have any further questions about any other aspects of garden lighting, we would be happy to assist. Please either contact us via Live Chat or email your query via the link below. We aim to reply to all emails within one working day (excluding bank holidays).