What is good light?

 

When buying a new lamp for our home we often forget that we have to live with it not only during the night when lightened but during the day too. A lamp is a companion we hopefully will live with for years and in more than one sense enlighten our life. But whatever beautiful lamps are offered, the source of light, the light bulb and the quality of light it is supposed to deliver, mostly become a surprise when the lamp is installed and switched on. Should it be warm light or cool? Is it for reading, eating or working or is it thought to create or support a special ambience in a special space. It all comes down to one crucial thing… the source of light. How much of it and at what degree of warmth or coolness is required? How far should the light beams reach out in the space the lamp is supposed to be enlightening? Shall it be diffused or sharp and bright light?  How much energy does an electrical light source consume relative to their efficiency?

All are very good questions to get answered when looking out for a new lamp!

 

For what purpose?

Lighting could be classified by intended use as: A general-, accent-, or task-lighting, depending on the distribution of the light produced by a lamp fixture.

Task lighting : Is supposed to be functional and is usually the most concentrated, for purposes such as reading, cooking or working with various tools and machines and may require task lighting levels up to 1500 lux*, and some tasks procedures require even higher levels.

Accent lighting : Is mainly decorative, intended to highlight pictures, plants, or other elements of our interior design.

General lighting : Is an ambient light that fills in between the task- and accent-lighting and is considered as a general illumination of a space or room. Indoors, this would be a lamp on a table or floor, or a fixture on the ceiling.

What is Illuminance = Lux?

Illuminance is a measure of how much luminous flux is spread over a given area. Think of luminous flux as a measure of the total "amount" of visible light present, and the illuminance as a measure of the intensity of illumination on a surface. A given amount of light will illuminate a surface more dimly if it is spread over a larger area.

One lux is equal to one lumen per square metre:

A flux of 1000 lumens, concentrated into an area of 1 square metre, lights up that square metre with an illuminance of 1000 lux. However, the same 1000 lumens, spread out over 10 square metres, make only an illuminance of 100 lux.

Surfaces illuminated by: Moonless clear night sky = 0.002 lux- Full moon on a clear night = 0.05–0.36 lux

Family living room lights = 50 lux- Office building hallway lighting= 80 lux - Office lighting = 320–500 lux

Very dark overcast day = 100 lux - Sunrise or sunset on a clear day. = 400 lux- Overcast day= 1000 lux- Full daylight= 10,000–25,000 lux - Direct sunlight= 32,000–100,000 lux

 

Light sources

The three key parameters.

Luminous flux is measured in lumens (lm) and indicates how much light is emitted by a light source. Power usage is measured in watts and was previously used as a standard for the quantity of light emitted by a light source. Since the filament light sources have been prohibited in many countries the use of watt as an expression for light intensity is no longer advisable because new luminaire technologies are far more effective than the traditional filament bulb which probably made 10% light only out of the total energy input; the remaining energy disappears as heat. Light sources can in general no longer be directly compared to other types because luminous efficacy varies greatly between the various types of light sources.

Here is a brief overview of power usage in watts (W) and luminous efficacy in lumens (lm) of various luminaries.

 

 
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The efficacy (output) of luminaires is measured in lumens per watt and is eventually a better expression for how much light you get out of the energy you put into a light source.

Filament bulbs: 10 lm/W

Halogen bulbs: 15-18 lm/W

Energy-saving bulbs: 50-60 lm/W

LED bulbs: 70-80 lm/W

Shortly expressed; energy-saving bulbs have 5-6 times more luminous efficacy per watt, and LED bulbs 7-8 times, compared to conventional filament bulbs.

 

Cool or warm light?

Colour temperature is measured in the unit Kelvin and is a standard for how warm and how cold a light source appears and feels. In general the blue-spectrum of visible light is perceived as being cool, red-spectrum light is perceived as being warm. The higher the Kelvin number, the cooler the light. The warm spectrum, which is characterised by a low colour temperature of 2,600 – 3,000 K. Comparable a filament bulb, will have a colour temperature of 2,700 Kelvin.

 

How to ensure true colours?

The ability of a light sources to reproduce or depict the entire visible spectrum of colours we find in our surroundings is measured in Ra or CRI (CRI = Colour Rendering Index)  – the higher the Ra/CRI number, the better the colour reproduction. Halogen and filament bulbs have a Ra/CRI rating of almost 100, while energy saving and LED bulbs have a Ra/CRI rating of 80 as a minimum.

Why a high Ra/CRI rating? Simply because colours delineate a light close to what nature, the sun, has set as a standard Ra/CLI 100 and is important in all environments but of course especially in kitchens, dining rooms and for reading and working purposes.

 

Types of light sources, what to choose?

The choice of a light source unfortunately depends, not only on quality of light. Function, power usage and purchase price are for many a far more important influencer on what light you put into your lamp.

LED light sources are a big technological step forward when it comes to power consumption and lifecycle length with up to 25000 hours, but its Ra/CRI lacks the quality of light we were used to in the filament bulbs.

Madetostay has taken the step to include A++ LED lights that can be dimmed simply to secure a balance between function in terms of colour (2700K) and the colour rendering index (Ra/CLI 95), power usage and the fact that these lamps parts can be recycled without harming our environment with dangerous chemicals.

 

LED

LED is short for Light Emitting Diode, i.e. a diode that emits light. LED light sources light up immediately; they consume little energy and typically have a relative good colour reproduction. A LED light source is comparable expensive, but has a very long service life. Some LED light sources can be dimmed for decreased or increase light output. A big part of their components can be reused (Approximately 85%)

Madetostay include in its cocooning lamps A++ bulbs with a service life of 25,000 hours, with 2700 Kelvin a warm light. Ra/CRI 95

 

Compact fluorescent lamps CFL

CFL bulbs consume little energy and have a long service life. They are relatively safe to use and is relatively inexpensive. CFLs are slow starters and from switched on to full intensity takes a bit of time annoyingly. Not all energy-saving bulbs can be dimmed. CFLs contain mercury and it is rather difficult to believe that the CFLs will be recycled in a proper way considering that these bulbs are now the main light source around the world. Each CFL bulb contains 4 milligrams of mercury and as long as it is contained in the tube it is not harmful; but mercury is dangerous stuff not only if leaked from the bulb, but throughout the entire lifecycle chain…from production to recycling, if it at all ends up in recycling facilities and not just discarded in landfills it will end up in the groundwater.

 

Halogen incandescent bulbs :

A halogen bulb does a very good job in terms of colour rendering and produces a warm full spectrum of light. It lights up immediately and is inexpensive. The negative side of halogens is that it consumes a lot of energy and has a short lifecycle (Aprox. 2000 hours) and therefore on a longer and shorter term be expensive compared to LED’s.

But still, it is delivering a perfect light of Ra/CLI of 100!

Light at home :

Lighting is not about lighting up a space only; it is the essential of our life and how we perceive our surroundings meaning the space you call yours, and it truly pays off seriously to consider what to buy new or what to exchange. Light shapes our life far beyond what we imagine, it is form and colours and it is shades of the things you desire. It is about moods, ambiance and eventually a cosy atmosphere at home; but foremost it is about creating a suitable light rendering every day life to the best of your physical and mental health. We know from scientists, health gurus and artists that light is important for our brain and its fierce activities, actually we can’t live without light! Light affects our ability to concentrate and enhance our physical wellbeing in general and scientific studies shows that lights influence on our health, goes far beyond what commonly is known .

It is although obvious that the light from the sun, even when it is shattered or filtered by dark clouds, is the best light for humans because our inborn biological and social clocks are dependent on the spectrum of light between daylight and the dark of night. But modern time has made us deeply confused with daylight and artificial light. They are simply no longer synchronised because we get too little of the one and too much of the other. If we would acknowledge this imbalance an outcry would be loud and we would scream: “More sunlight to the people!” “Adjust artificial light to its needs!”… artificial light is polluting our world! Since the rooms in your home have different functions, lighting should follow these needs and sometimes one room has several needs.

Different types of lamps in your home can be switched on and even dimmed to your needs, offering us flexibility. It is not just about switching on and bathing the entire room in light; but to provide different choices for different tasks and moods creating variations of light in the same room. Opposite to a professional light adviser, who wants as much light in a room as possible and gets dark corners banned for darkness, I strongly object! Give shadows and darkness in a corner a chance! How much and how little should be your choice, but you have the needed technology at your hands to craft your personal space and millions of well designed lamps to choose from that can satisfy your needs! What we need to say is that artificial light is best in a combination of diffuse and direct light? Diffuse light is soft light that illuminates a room. You can create diffuse light by using lamps cocooned with glass, paper and eventually the cocooning material of the madetostay lamps. The material light is refracted or better filtered by soft diffused light.

On the other side the effective use of direct light appears when light is projected onto a surface with the qualities of the light source and at the same time are shielding the glare from the light source. Being able to dim light according to the tasks you have will enhance concentration and doesn’t send tired eyes on flickering detours. The madetostay T-house lamp satisfies in a simple way such demands because the included LED light sources are suitable for dimming and can be adjusted for a more narrow or wider light cone and thereby lightening a smaller or bigger space of say a table. Please remember that expanding the lightened area with the same amount of lux means that the light gets weaker all over the lightened space.

 

Light in a living room?

Living room has several different functions. Think it over what you usually do in the room and what will make you relax and be comfortable in these situations. The intro has given you some simple guidelines to follow by each of your living room activities whether playing chess or taking a horizontal position on the couch with a book or an i-Pad. Make a composition of light throughout the room and go for “functionality” first, followed by quality of light and how to mute the room into a personal ambience.

 

Light in a dining room.

Enough light meaning amount of Lux! The right colours; meaning Kelvins, warm cold and finally the best possible colour rendering of the food to be served meaning Ra/CRI. Since many dining rooms are now one and the same room as the kitchen, it comprises many daily activities beside that of dining, like kids homework, it might be appropriate to have a certain multi functional lamp or several, to enlighten the dining table and the young genius and the food to be served. But tables are not only a domestic landscape of food and French vocabulary it is as well the setting of moods at dinners. Dimming the light source could be a good substitute for oozing candles. Light changes how we see people and a blazing light shower makes faces with sharp aggressive shades! Not enough light could send the same faces into a murky disappearance and we will no longer remember who was at that dinner 10 years later. It is important to suspend one or several lamps over the table in such a way that the entire table area is illuminated. Consider that you must have the possibility to entertain your guest unobstructed under the lamp object and the light it provides.

Again it will become a matter of personal wishes if it shall be a diffused light illuminating the entire dining room or it shall be direct light illuminating like actors on a stage in a theatre? Eventually both and may be even at different time during the dinner by having the option to dim the light.

 

Light in the kitchen?

Kitchens are surely the most essential space in a home for good. Preparing food is a craft that needs motile skills and therefore the best light you can find to prevent accidents and make the preparation of food a visual, tactile, olfactory and gustatory sensation. Light plays in all our sensory faculties a role; it is like an instrumentation of a symphony to which you can be humming in delight when you have the right light! Make sure your light sources have an adequate colour reproduction rating (Ra/CRI), so you can see the colour nuances of the food you’re preparing. Suspend several lamps so the light is dispersed evenly and so that it covers the preparation and cooking areas. Wall lamps can be combined with pendant lamps with good effect.

Invest in light sources for the task lighting with a quality colour rendering index of at least 95 to 100: they make your food look natural and appetizing.

 

Lighting for bedroom?

Considering that the most of the time we do not need light in a bedroom, the reason bedrooms are often ignored and bad lighting the result…people sleeping don't sin…but there are no absolutions from bad light in bedrooms.  Actually ambiance bedroom lighting is as important as in any other place of the home and not least perfect bedside lighting with the right light sources is essential. Combine pendant lamps with diffuse light with wall or table lamps with direct light, which can be adjusted so that it shines out to where you want to have it when turning around in the bet of excitement when the crime unfolds on page 120 in your book.

 

Lighting for home offices? Reading light.

Reading light can be coming from a floor, table or wall lamp, and may be even from a suspended lamp. It makes sense to place the light or yourself in a position that the light doesn’t fall 90° orthogonal to the page but rather in a diagonal direction across the pages. In this way a certain contrast and shadows occur and preventing tired eyes.

Remember, we were all warned that reading in poor light would ruin our eyes. But are poor reading lights really the cause of vision loss? Contrary to popular belief, the answer is no! Reading in low light does not ruin eyesight. Most eyes worsen simply due to ageing. Good reading light can reduce uncomfortable short-term effects such as headaches or eyestrain as well as make reading more enjoyable.

To reduce the conflict in your eye muscles when you’re completing a high-concentration task such as reading, it’s important to focus bright light at a certain angle where it is needed. The angle of light enhances contrast and shadows and has a pleasing relaxing effect on your eyes.

A common mistake people make when choosing light for reading is turning on a bright lamp in a dark room. Your pupils dilate from the dark when they wander off the page, which can make your eyes become easily fatigued – a reason many of us quickly become tired when reading in bed at night.

Reading by light that reflects a lot of bright glare, such as from a computer screen can put a lot of strain on your eyes. It is called a Computer Vision Syndrome and is a truly underestimated health-damaging factor.

Eyes vary with age and as your eyes get older, you need more light to read. The need for more light to read by increases 1 percent a year; meaning by the time you're 60, you need around 100 watts.”

Keep in mind that too much light or glare can be just as bad as too little light. When light glares from highly reflective surfaces it's fatiguing. So if bright light is making you uncomfortable, make use of a shaded lamp rather than a desk lamp to decrease glare and moderate light. Light in the warmer end of the visual spectrum is easier on your eyes than in the cooler end of the spectrum.

At the end of all theories and science your eyes will tell you what they want…it is a good advice to take them serious and adjust to their reactions!

 

How much lumen do you need for each room?

A simple overview of approximately how much light is in demand in the various rooms throughout a home.

Kitchens : 5,000-10,000 total lumens

Bathrooms : 4,000-8,000 total lumens

Bedrooms : 2,000-4,000 total lumens

Living rooms : 1,500-3,000 lumens

Dining rooms : 3,000-6,000 lumens

Home offices : 3,000-6,000 lumens

Keep in mind, these are very rough estimates and account for having different types of bulbs and lighting options in each room. Size, materials and colours in a room influence the perception of how much and how little light is needed and the ability to adjust the output of light is a perfect way to find the right amount of lumens for a specific space and specific event that will personalize lighting.

  

Lighting in offices and public spaces.

Madetostay’s ambient and task lamps are surely available for use in all professional possible illumination projects. Since our producing partners has more than 50 years of lighting development experience we can offer professional architects and designers the opportunities to create site specific design projects whether you’re furnishing a restaurant, a shop, a hotel lobby or an office.

In site-specific contracting projects, we recommend undertaking analysis of needs and functions of the lamps. Consider how the space will be used and confirm lighting requirements. Check functional requirements for the lamps themselves such as energy efficiency or if a central intelligent lighting control system is in demand. Regulatory requirements must as well be analysed and confirmed by national and local authorities before a project or a development can take place. We shall be pleased to assist in all possible and impossible projects.