From time to time we are checking the internet for what people say about Viva-Lite. That way we can learn a lot how our customers perceive our brand, products and services.

For example see this feedback on namahatta.org and how well Viva-Lite worked for growing Tulsi:

“We planted Tulasi at home last summer. When she was very little we bought her a 26 W Viva-lite full-spectrum bulb. She was doing well with it. She grew very strong stalk and large, green leaves. Recently we felt she needs more light. We arranged two 36 W fluorescent Viva-lite tubes for her. In Scandinavia there is hardly any natural light at this time of the year!

As far as I’ve understood, plants benefit mostly from certain wavelengths of light. In order to grow nicely, they need more cool or blue light. When they are blooming, they require some red wavelengths, too. Visual color temperature is measured by the degree of Kelvin. That’s what you have to pay attention to when choosing light for Tulasi.

Full-spectrum lights are as close as it artificially gets to a natural mid-day sun during the late summer. Viva-lite bulbs/tubes have 5500 K which resembles normal daylight. They imitate all wavelengths of light to some degree. Because they have a very high color rendering index (CRI), they don’t distort the actual color impression around them. Lights that have low CRI make everything look weird, either yellow or strangely blue.

The standard incandescent or halogen lamps have around 2500-3000 K, which is not useful for plants. They also emanate a lot of heat and waste energy.”

We couldn’t agree more. Visit namahatta.org to read the full article.

Related posts:

1. New Year Amaryllis – Happy And Alive!
2. Why do plants respond to full-spectrum light?
3. The Colour Rendering Index (CRI)

What does Wikipedia have to say about the CRI: “The color rendering index (CRI) (sometimes called color rendition index), is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications such as photography and cinematography. It is defined by the International Commission on Illumination as follows: ‘Color rendering: Effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference illuminant’.”

As this sounds a wee bit complicated, we’ve prepared an article which (hopefully) explains a bit mor simple what the CRI is and does. First of all, please note that the CRI is different from the light colour or colour temperature of the lamp. Even so-called “daylight” bulbs may have a comparatively low CRI (as per full-spectrum standards anything below 90 is seriously low) and it is the CRI rather than the colour temperature (measured in “K” for “Kelvin” by the way) which makes the real difference when it comes to the light spectrum and ultimately how good you’ll see and be able to do visual tasks under such lighting.

Researchers in Sweden found out that with the CRI being around or above 96 Ra, it is quite possible that we see up to 30% better when compared to lower quality light sources. So what light sources are those which are preferrable for a good CRI which are those who are not:

I light source with a CRI = 100 Ra would be perfect and balanced in terms of colour reproduction, shading, contrast etc. – therefore the lesser the difference from 100 Ra, the better will colours be reproduced under such light. The lower the Ra-value, the worse colours will reproduced and the more difficult it is to see and work under such light.

A last but important word on the note of colour reproduction:

When comparing different light sources, it is only recommendable to compare them in the same colour temperature. It makes therefore not much sense to compare an incandescent 2700K bulb with a 6500K daylight energy saving lamp. For a proper comparison – either the incandescent lamp should be also rated at 6500K colour temperature or the energy saving lamp should be in the 2700K range. Then – and then only – true colour reproduction comparison can take place.

We hope this helps to clear up some confusion around the terms colour reproduction and colour temperature. Thanks for reading

Related posts:

1. A funny Colour and Reading Speed Test
2. What Light Looks Like
3. Lights for Tulasi