Back in the 70s of the last century, scientists and researchers in the field of light began to measure and evaluate the quality of color rendering from various sources, while describing the result obtained with just one number.
This parameter or coefficient was called CRI. It also has another designation - Ra. Essentially it's the same thing.
CRI stands for Color Rendering Index - color display index.
What is CRI
It is he who is responsible for the fact that the same orange, in one case, will look quite natural, and in another will not look like itself at all. This is called natural color reproduction.
By the way, many probably remember the riddle that divided the Internet into two camps - “what color is the dress in the photo”? This index played a significant role here.
That is, coefficient. answers how natural and natural an object looks under a particular lamp or lighting. For you it may make no difference, you will still eat an orange or wear a dress, but for an artist or photographer this parameter is oh so important.
By the way, this point applies not only to the process of painting a painting, but also to its display in galleries.
It can also increase or, conversely, decrease sales in grocery stores. Not everyone wants to buy a suspicious-looking lemon or other fruit.
Although in fact the products will be absolutely ripe and healthy, the whole picture will be ruined by incorrectly chosen lighting.
In exactly the same way, supermarkets can deceive. You buy seemingly beautiful and ripe apples from a display case, bring them home, unwrap them, but they no longer look as appetizing as in the store.
They certainly could not have deteriorated in such a short period of time, but we must pay tribute to the local staff, who, unlike you, were familiar with the concept of color rendition and selection of the desired CRI.
Important aspects
When choosing LED lamps for your home, you need to pay attention to the caliber and type of base, as well as the size of the bulb. Before purchasing, you should measure the lampshade or even take it with you to avoid purchasing a light bulb that is the wrong size.
For lamps used for domestic purposes, it is worth choosing devices with a color rendering index CRI of more than 80 Ra at a color temperature of 2500–3500˚K (warm white). The best light dispersion is provided by sources with a flux dispersion angle of 150–170˚. They are best used for ceiling lighting fixtures. For decorative or spot lighting, it is more advisable to purchase devices with a luminous flux angle of up to 40˚.
Some lamps are equipped with light intensity controls. Such devices are more expensive than conventional LED devices, but have several advantages:
- the ability to change the brightness of the lighting in the room;
- higher quality product execution;
- high efficiency;
- extended service life.
Disadvantages of tunable lamps:
- high cost;
- restrictions on the scope of application.
Based on the information given in the article, everyone will be able to choose ice that will not only reduce energy costs, but also provide comfortable lighting for any room.
Light spectrum and its influence
Maximum CRI value=100. This is exactly the coefficient of sunlight. For artificial lamps, the higher it is, the better.
Of course it’s great to have an LED energy-saving light bulb that imitates the sun 100%. But firstly, this is technically difficult to implement, and secondly, it is unreasonably expensive.
However, do not confuse concepts such as “color temperature” and “color rendering index”. These are different things.
For example, two lamps can simultaneously have the same temperature, but they will transmit colors completely differently.
Before moving directly to the index and its calculation methods, it is worth recalling what the spectral composition of radiation is. After all, this directly affects CRI.
So, any light contains several colors at once. And everything that surrounds us absorbs or reflects these colors.
Moreover, objects or plants that appear green therefore have this color, since it is green that they reflect. All other colors on their surface are absorbed in this case.
Although for the most part, color is formed in our head. It's a feeling. Anyone who has “got it in the eye” can confirm this
