Category: lighting

Birds and flickering lights

Birds and flickering lights

What is flicker?

In its simplest definition, flicker is the constant fluctuation of light output from on to off.

LEDs: Fighting Flicker

In the US, the power that comes in through our outlets cycle at 60 times per second. Instead of one continuous stream of electrons, it goes ON and OFF 60 times per second (referred to as 60 Hz). Many light bulbs also flicker at 60 Hz and cycle towards full brightness and full darkness. We call that the flicker rate.

(I’m going to gloss over this but the circuitry connected to a light source can create light that is a higher flicker rate than 60 Hz. Many fluorescent bulbs are 120+ Hz for example, and some LED lights are even higher than that. This is an extremely technical discussion that you can read more about in the research I’ve referenced in this article).

Many people never notice the flicker, but we probably all know at least one person that can see it in a light bulb or TV or computer monitor.…

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The truth about full spectrum lights

The truth about full spectrum lights

I touched briefly on full-spectrum lights in my article on UV light myths.

So what does full spectrum mean? Well, it means something different when it comes to light and to light bulbs.

For light:

Full-spectrum light is light that covers the electromagnetic spectrum from infrared to near-ultraviolet

Full-spectrum light—Wikipedia

For light bulbs:

“Full-spectrum” is not a technical term when applied to an electrical light bulb. Rather, it implies that the product emulates some important quality of natural light.

Full-spectrum light—Wikipedia

There is no agreement and there are no standards for what constitutes a full-spectrum bulb. This may come as a shock if you’ve bought bulbs labelled as full spectrum, which typically are priced higher.

It’s not to say that every manufacturer is lying, but rather than trust the labeling, it’s better to understand the qualities of natural light and try to buy bulbs that have many of those qualities. There is no such thing as a bulb that perfectly emulates natural light.…

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UV (Ultraviolet) light myths

UV (Ultraviolet) light myths

This will probably be the longest article I’ll ever write because the internet is full of so many inaccurate statements. I’ll go through each myth one by one.

Myth #1: Any ultraviolet light can cause a bird to synthesize Vitamin D

There are actually two relevant types of UV light: UVA and UVB. Most articles about birds and lighting don’t specify with type and just say “ultraviolet” light.

So, first let’s establish that it’s UVB light that is required for Vitamin D synthesis.

During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UVB radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3.

Sunlight and Vitamin D: A Global Perspective on Health—Dermato-Endocrinology—’Jan 2013

UV light causes the body to produce vitamin D (specifically, UVB), which is essential for life.

Ultraviolet—Wikipedia

In humans, both UVA and UVB are responsible for secondary effects on the skin such as erythema (sunburn) or tanning, but UVB is the only range associated with the photobiochemical synthesis of vitamin D3.

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Case study of “How do I know who to trust?”

Case study of “How do I know who to trust?”

I wanted to provide an example to back up what I wrote about in How do I know who to trust? I wish I could say it’s easy to spot misinformation, but it does get easier over time.

I could’ve picked any number of articles, but I chose this one to illustrate how I determine a trustworthy source.

Proper lighting to support avian vision

On the plus side

  • It comes from a seemingly credible source, one of the largest bird rescue organizations in the US
  • Clearly a lot of effort was put into writing a very wide-reaching article that is presented and formatted nicely and with images

On the minus side

This article has a number of obvious red flags to start off with:

  • No author is listed as well as no contact information
  • No sources are cited for an article that is highly technical and critically important to bird health

Analysis

Now I’m going to go through the article and quote some bits of it and explain the concerns that I find.…

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