Let's start this conversation out with two things that I am sure will have everyone sitting up in their chairs!

1. There is no such thing as "full spectrum light"--natural or artificial. This is a relative term used to describe something that is completely variable, and has no precise meaning.

2. A fid which is properly fed does not need UVB for its Vitamin D.

Number one is a good place to start! When we say full spectrum sunlight what are we talking about? Merely the light that appears under a variety of conditions across the earth. But where? are we talking about a perfectly clear midsummer's day at noon in Venezuela--at sea level, or in the mountains? Or is it a clear midsummer day at noon in Calgary?

The spectral content and power distribution of light varies by latitude, altitude, season, and time of day. "Normal" sunlight can vary on a clear day from a color temperature of 3600K at sea level to the upper 6000K range or more at high altitudes and latitudes. For our little tropical friends in the wild, they spend the majority of their time in a daylight environment that is between 5000-5500K. A crow in Kansas might have a preference for 6000K light, whilst a penguin in Antarctica would prefer something much higher!

Fluorescent lights "trick" our brain. They use a mix of three phosphors on the coating that emit sharp energy bands in the primary colors. Using the principle of additive color, this mixes together to make what appears to be white light--more or less. It is awfully lacking in some areas and our brains fill in the details. There is now, and never will be a fluorescent light source that by its own merits can accurately mimic sunlight. But for reasons we will discover later on, a 5000-5500K lamp is appropriate for giving our fids artificial light.

Probably having stirred up enough controversy there to last a few days, my work is not done! Let's stir the pot some more with number two...

Quality fluorescent solutions either do not put out the wavelengths necessary for natural cholesterol synthesis of Vitamin B precursors, or do in such limited amount as to be fairly useless. Certain reptile lamps do, but do not get confused--you own a bird and not a reptile. Let's not mix them up...

The majority of caged and pet birds in the world receive little or no UVB that can do anything for them. Some of our birds do not even have the gland necessary to do this anyway. So how do they get it, regulate calcium metabolism, and stay healthy? The answer is diet.

All quality commercially prepared diets contain certain "pre-vitamin D" chemicals--ones that can easily be converted to the active form by the liver and kidneys--without light playing any role. Many others are supplemented with pure bioavailable D3--it is even sprayed on certain seed/grain mixes before packaging. The same is true for homebrew diets that are rich in calciferol and cholecalciferol (D2)--green vegetables, fish & fish oils, egg products, yeast, and several others.

Then why bother with "full spectrum" lighting for birds? It has to do with extending their vision to what is normal for them, regulating overall endocrine function and metabolism, stress levels, molting, and breeding condition.

Questions or opinions? Next we will get to the heart of what this CRI thing really means!

Buy wouldnt regulating metabolism and endocrine function help produce needed vitamins like D3? I use full spec lighting but question its affect.

Patrick thank you for taking the time to educate about this topic. I'm all eyes and look forward to your follow-up posts.

thank you very much patrick, that was very informative and helpful! i am wanting to learn more on "full spectrum" lighting and this was a great start. i look forward to your future postings

Patrick..... I have read with great interest your current posts on this Board as I have read your previous work. Based on everything you compiled and published in the past, I have long used "full spectrum lighting" for my indoor birds (with electronic ballasts and 2 of the four ft. linear Phillips 98 CRI tubes in each fixture, K Temp. of 5,000). These were recommended as best, I thought, in the compilation of articles by you and I even advocated the use of same to others. So what exactly is it about your new tubes that will cause me to want to spend $54.50 for two (does that include shipping and tax btw?).

I want to know how exactly your product line is specifically that much better for my birds - will THE BIRDS truly be able to see that much better etc. & how do you know for sure. Do you have birds that you have used them on and compared that use with say maybe the Phillips tubes that I already use = Philips F32 T8TL950 (about $7 each when buying a box of 25 - are you going to give discounts for quantity purchases, if so - how much and how many would one have to order = 4ft. length? I am at least glad I will be able to use them in my current light fixtures (if I order them that is) - which have electronic ballasts of course.)

Sheesh, after I spent all that money and time trying to get what I thought was the best lighting for my birds, based on info. from you, now you are saying your new product line is THE BEST, if I am not mistaken? So what do I do with all these tubes I have left, new in the box? Are you saying they are of little or no value to the birds, comparatively?

Guess I will just have to buy at least two of your tubes, install them near two of the Phillips tubes I use now and then decide for myself which are better, best? I wonder if I will truly notice any improved health etc. in my flock members.

I would appreciate knowing the sources for some of the conclusions you have stated in your post - like your statement that "A fid which is properly fed does not need UVB for its Vitamin D". I am not trying to pick any fight with you but you are challenging certain assumptions I have made for many years (that the lighting I was using was the best available for my birds and that FS lighting was beneficial for regulating the metabolism of calcium) and would like to review your sources/experiments so that I may assess them myself. Lastly, do you know yet what Phillips is going to say about your product line and research?

To Leigh & J:

Please bear with me here, as I am trying to not put too much information into a single post. Everyone gets lost in the details that way, and it does not afford any of us the opportunity to clarify what has been posted to date.

First to Leigh. Yes, calcium metabolism is a very important thing--and is a PART of the overall mineral level requirements--as is the entire endocrine function of a bird for general health. When considering adding lighting (if it is a necessary part of enhancing the environment), we are looking at a total picture. Let me state this. Birds that are in a sunroom aviary environment or positioned directly near a window that receives ample sunlight from the south, east and west will likely not need an additional lighting solution. Their needs are being met.

Consider adding lighting for those birds that are in an interior room, or that the light comes predominantly from the north, that do not receive good light, or are experiencing behavioral or health issues. So in those instances where ample, quality natural light is lacking, additional lighting is very beneficial.

To J:

Rest assured that you are choosing the best currently available "general human" environmental lighting option with the Philips. As the discussion progresses, I will explain why that is--and how developments to that platform that can benefit avian vision and health. While I may speak in very general terms of the kinds of technology advances that are available today, I will not tout my own product--or for that matter any other product that has not established itself in the generic market for at least 5 or more years. To do so would not be objective, would not constructively add to the conversation, and presents ethical problems. I will be happy to address your question about that in a thread on the "Products" or "For Sale" board. This thread is strictly for overall education on the subject.

I will be more than happy to provide you with monograph references to anything I say (please PM me with your email address)--however the evidence is right in front of you. The vast majority of bird owners are not employing any artificial lighting for their birds--and many are located in less than optimal locations for natural light to be a part of the ambient environment.

Yet you will be forced to admit that there is not an epidemic of calcium metabolism problems in that population. Locating next to a window is a poor argument for why this is apparent--All UVB, and a majority of the UVA is lost through glass absorption and scattering within about 1-2 feet of the window. Unfortunately the UVB myth is one of the hardest to break--as it has been promulgated by well intentioned bird owners and sellers of lights for years.

As to what Philips may contribute to the discussion, I may assure your that it will be nothing. They manufacture the basic tube/phosphor assembly for us in the Netherlands, and we apply coatings and other proprietary technologies here in Kentucky.

Next topic, CRI!

Thank you!

In previous threads on this subject, several owners and a supplier of avian lighting have made the claim that the CRI of a lamp has to do with its color temperature or whiteness. This is untrue.

CRI stands for Color Rendition Index, and is a relative measurement of how well a source of light can enable a viewer to make distinctions in color variations. Let's consider it this way.

Light from a source combined in any way results in what is known as an additive process. A diagram is attached to illustrate that. However, things that exist in nature are comprised of pigments that absorb certain spectral frequencies, and reflect others. This is known as the subtractive color process. See the next diagram.

When light strikes an object, it is reflected back in a certain way--depending upon how the properties of the object absorb light. As we know, there can be very subtle variations in color--a slight shade of difference that adds detail and depth.

The color rendition index of any light source--with sunlight as the top dog--gauges the quality of the light in its ability to render those subtle variations discernible. The higher the CRI of the light, the better we can perceive those variations and make a distinction. Whiteness or in other words, color temperature, it determined by the Kelvin (K) rating of the lamp.

Excuse me if I state this strongly, but anyone who states that there is little difference between a CRI of 91 or 96 as contrasted to 98, 99, or 100 is either ignorant or attempting to mislead their audience. CRI is not an arithmatic progression (as in 1+1+1=3), but a geometric progression (1+2+3=6) for each step of the rating. Doubt me? Do a Google search, and/or read the articles on color space and rendition in Wikipedia.

By natural law of physics and man's law, the composition of trichromatic phosphors limits the effective CRI of tubes to 98. Compact fluorescents are limited to about 96, By man's law, I refer to the composition of the phosphors that are dictated by federal law to meet certain minimal energy efficiency ratings.

Museums, photographic & art galleries, and commercial photographers are well aware of this--the Philips TL-950 line was designed for and is marketed to fit this need. This is why they are so difficult to locate--a specialty item.

We can however augment the performance of high CRI fluorescent lamps--but not through their phosphor balance which has extremely high peaks and valleys (see attached thumbnail). This is accomplished through the use of optical filters and absorptive coatings--something usually only done in the laboratory or testing environment with carbon or xenon arc sources.

To sum up, the color temperature in Kelvin (K) determines the "whiteness" or more appropriately 'blue balance' of a light source, while CRI indicates how well subtle colors can be perceived under a particular light source. Occassionally one will see the terms CCI or CCT (Corrected Color Index and Corrected Color Temperature) referred to in lighting.

These ratings only apply to metal halide light sources like you may encounter in a large warehouse or store like Wal-mart. They do not apply to fluorescent lamps and anyone who uses them to sell you something is trying to hoodwink you!

I fear that this dollup may be a bit much for some--be of strong heart!

Attached Images

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	400px-SubtractiveColor.svg.png (19.4 KB, 4 views)
	tl950-graph.jpg (51.8 KB, 3 views)

awesome stuff!!! So the idea that CRI differences are in sequences of 10 is hooey? I believed it was bunk info as I can see a difference in the 91 CRI in my kitchen light (5600k) and the 98 CRI (5000k) for my birds which are next to each other.
I had been told not long ago that the term "full spectrum lighting" was a marketing term not scientific?

Jim, I love your avatar. Many years ago, I worked as a portrait photographer in a large and busy mall environment. For some time I deluded myself that I was the observer of the human zoo that paraded past me each evening. One day the reality descended on me--I was the one confined to a cage and the visitors were watching me!

Your assessment of the "multiples of 10" paradigm is correct. I had never heard that before, and someone really had to reach around and dig deep to pull that one out. There is not a single factor in reality that even by the longest stretch gives any credence to this claim. Sounds to me more like marketing hype to cover up and cosmetically buff something of lesser performance.

As always, Google the keywords presented to you. The corroborating literature is often found on jstor, EEIA, or similar electronic archive. They want you to shell out dollars for access to the document--but if you live near a university titles are most often available through their electronic subscription services, periodical stacks, and a small copy charge through Inter-Library Loan systems.

Most often though, some university or creative individual has placed an informative site up that gives an abstract of the general information--many times with graphs and charts.

As to the label "full spectrum", this was a creation of John Ott. I had the opportunity to work around some of his environmental experimentation in the early 70s at New College in Sarasota, Florida. His most efficient device at the time had a CRI of maybe 83... A staggering improvement over the single phosphor halophosphate lamps of the time.

For the lighting engineer and the consumer, "full spectrum" has quite different meanings. There are definitive standards and benchmarks--these are reflected in an American Society for Testing and Materials specification (ASTM E308), and even more precisely, the Commission Internationale de l'Eclairage/International Commission on Illumination (CIE 15.2), and the International Standards Organization (ISO 5, Part 3).

From these qualifications comes the benchmark that FS be 92 or above, with the ideal 96 or greater. These are primarily based upon the 5000K standard. When I began publishing my research in 1999 and 2000, I was a little more liberal due to the bulk of the devices available at the time on the domestic market. When the site is moved and updated (which it has not been for nearly 7 years), some of the values I gave will be updated and certain low performance products removed from the charts. Advertisers and marketers are much more liberal--in America the Federal Trade Commission does not recognize or enforce any standards by which a claim may be judged. Here, as opposed to Europe where a lamp must be 96 or above to qualify, is the doctrine of CAVEAT EMPTOR--let the buyer beware.

A lot of manufacturers are happy to show you "performance" graphs--most are works of creative fiction--using very broad based spectral ranges to make their lamp outputs look smoother. And very few are Total Spectral Power Distribution [SPD] graphs of 10nm increments or less--ones of 50 or 100nm units are useless--and the contrast to the "normal" curve of sunlight radically scaled to look close. Sometimes it makes me want to...