Tomatoes are red, or are they?

Tomatoes are red, or are they?

So what, you may ask!

It is relevant to ask a question like that. If you don’t think about how the food look like or have a feeling how it should look like, then your food is just a necessary evil time consumption devil. Of course food is important how it taste and look, me myself could spend hours in the kitchen just to get the correct smell and taste. Food is a necessary part of life…  

Take a look and do so in a really good lighting environment

In the new low energy consumption society we sometimes accept something we shouldn’t do. So ask yourself again are the tomatoes red? Take a look again and do so in a really good lighting environment, certainly not under fluorescent light or low energy bulbs! Take a look at the tomato under a LED light with CRI 95 or higher, or take it out under the sun, you will see a totally different tomato: it suddenly sparkles, thanks to different red colour consistency in the light. Isn’t a sparkling red tomato much tastier under a good light?

Nothing comes easy!

Maintaining high CRI might be a problem when we look at LED solution since the light output has to be compromised: a drop from 140 lm/W to 90lm/W on LED level. In another words, the light output increases with more than 50% if the LED is designed to be set at CRI80 instead of CRI95. This is important to know when a new design takes place because neither setting is wrong. Still there is a similar amount of energy emitted from the LED modules at higher CRI to those at lower CRI. Major difference lies in that the CRI80 LED has much lower light output in the deep red area than CRI95, this leads to the next question: where is it necessary to have this deep red colour? Human eyes have lower absorption on deep red than on normal red colour. In order to see different variations of colour, the LED module must be able to emit all different colours so they can reflect all into the human eyes. Nothing comes easy!

What is good enough?

For us companies developing LED modules, it is much easier to develop CRI80 as a standard due to easier and better access to phosphor solutions. However there are solutions where CRI 90 or 95 are necessary to implement such as in Medical lighting or high end Retail Lighting. Meanwhile, CRI 80 has to have some red in it to be good and then it will be good enough to be used in home environment or retail business.

So, what is good enough for you in retail lighting?

  • Vegetables CRI90 is a must especially with high R9
  • Meat CRI90 is a must especially with high R9
  • Retail in General CRI80 is mostly used
  • Fabric and cloth CRI90 should be used

 

I use my Oyster card to get as quickly as possible between A and B in the traffic of London, it doesn’t help me go faster in the traffic in Stockholm. Maybe a bad reflection but it’s the same with CRI you use it according to what you want to achieve!

If you want the food to taste good it has to look good as well, it is an important fact so judge wisely how you should do. What light source are to be use!

 

By Stefan Larsson, founder Optoga AB.