个人感觉很棒的一篇文章--水族缸中的光谱选择（译自水族驿站）

mynameismo

个人感觉很棒的一篇文章，有理有据，分享给大家，内容有些长，好研究的鱼友可以一起讨论，翻译不妥之处请指证。原文出处http://www.advancedaquarist.com/2012/10/aafeature

目录
一、海水中的光谱分布
二、珊瑚显色的成因—色素蛋白--5楼
三、人眼的视觉特性--6楼
四、珊瑚的荧光发色特性--7楼
五、光强对于珊瑚显色的影响--8楼
六、LED的优势---15#、16#
七、光的色彩特性--17#、18#
八、LED灯光谱配置--19#、20#

一、海水中的光谱分布
Perhaps every reef hobbyist is willing to provide the "right" light to his corals - both correct spectrum and sufficient intensity are important. Before we consider how to implement this "right light," we shall first try to understand what kind of light marine organisms get in their natural environment.
As our starting point, consider the spectral distribution of solar energy in Fiji in July, Fig. 1:
也许每一个礁岩爱好者愿意提供“正确”的光给他的珊瑚-正确的频谱和足够的强度是重要的。在我们考虑如何实施这一“正确的光”，我们要先了解海洋生物在自然环境中是什么样的光。
我们从七月斐济的日光光谱出发讨论以下问题


Fig. 1 Spectral distribution of sunlight energy at the level of the sea
图1光能量在海中光谱分布


The horizontal axis of the graph is wavelength, in nanometers, and the vertical axis is spectral irradiance, in W/m2·nm. The human eye is sensitive to radiation in the range between approximately 400 and 700nm, therefore we marked the wavelength ranges shorter than 400nm (ultraviolet light) or longer than 700nm (infrared radiation) in black, whereas visible wavelengths are colored as they are perceived by the eye.
The chart in Fig. 1 has been obtained from the solar spectrum at the boundary of the earth atmosphere using the SMARTS 2.9.5 scientific simulation software. This simulator takes into account light absorption by various components of the atmosphere as well as scattered light from the sky.
该图的横轴是波长，纳米，纵轴是光谱辐照度，单位：W /平方米·nm。人类的眼睛是在约400和700nm范围辐射敏感，因此我们把短于400nm波长范围（紫外线）或大于700nm（红外辐射）显示为黑色，而可见光波长的颜色也由眼睛感知。
图1中的图是使用SMARTS 2.9.5科学仿真软件模拟边界的地球大气层的太阳光谱。该模拟器考察大气中各种成分的吸收光以及散射光。

Let us now try to find out what kind of light spectrum is available to marine organisms in their natural environment. In our attempt to build an ideal light fixture for our reef tanks we shall try to generate a similar spectral distribution at certain depths underwater.
现在让我们尝试找出什么样的光谱在自然环境中可对海洋生物是适宜的。当我们想要试图为礁岩缸建立一个理想的灯具时，我们需要在一定深度的水下生成一个类似的光谱分布。
Different coral species live on various depths: some live in very shallow waters, whereas deep water corals, such as Bathypates spp., can be found on the depths of up to 8000 meters (about 5 miles). About 20% of all coral species are non photosynthetic; they do not require any light as a food source. Most corals, however, are photosynthetic, and these are the species which are kept most often at home aquaria. We shall try to figure out what kind of light they prefer.
不同的珊瑚物种生活在不同深度：一些生活在很浅的水域，而深水珊瑚，如bathypates属，可在深达8000米的深处（约5英里）。大约20%的珊瑚物种是非光合的；他们不需要任何光作为食物来源。然而，大部分的珊瑚是光合的，这些是在家庭中最经常被饲养的物种。我们将尝试找出他们喜欢什么样的光。
Consider the graph of solar light penetration into marine water, depending on wavelength, compiled by the Institute for Environment and Sustainability of the European Commission [4] (Fig. 2):
太阳光穿透海水的光谱图，根据波长来绘制（横轴是波长），通过环境与欧盟委员会[ 4 ]可持续发展研究所编制的（图2）：



Fig. 2 Penetration of light into seawater, depending on wavelength
太阳光穿透海水后的光谱图，根据波长来绘制（横轴是波长）


The horizontal axis is the light wavelength, in nanometers, and the vertical axis is depth, in meters, at which the intensity of that wavelength is equal to one percent of the intensity at the surface. It is clear from this graph that wavelengths between approximately 370 and 500nm best penetrate into the depth. In other words, violet and blue parts of the spectrum penetrate best into seawater, whereas green light is much worse at that, yellow-orange is even worse, and red light with wavelengths longer than 600nm is only capable of penetrating very shallow waters.
水平轴是光的波长，单位nm，垂直轴是深度，单位米，在该深度的水下光强等于水面百分之一的强度。从图上看出在约370和500nm的波长有最佳穿透力。换句话说，紫色和蓝色的部分更容易穿透海水，而绿色光穿透力较弱，黄橙光更弱，而波长600nm是唯一能够穿透很浅的水深红光。

The light spectrum on the surface can be defined as a function I0(λ), where λ is the wavelength and I0 is the intensity for corresponding wavelength at zero depth. Hence the adsorption spectrum Ia(λ) at the depth D can be determined as
Ia(λ) = I0(λ) · K(λ) · D (1)
where K(λ) is the adsorption by marine water as a function of wavelength.
The spectrum at the depth D will be equal to the spectrum on the surface I0(λ) minus the adsorption spectrum Ia(λ):
I(λ) = I0(λ) - Ia(λ),
or, by substituting (1) into this expression, we shall derive:
I(λ) = I0(λ) · (1 - K(λ) · D) (2)
From this expression we can derive the graph of light penetration into seawater d(λ):
d(λ) = (1 - I(λ) / I0(λ)) / K(λ)) (3)
Providing that the graph in Fig. 2 is based on the assumption that light intensity on the specified depth is equal to 1% of the intensity on the surface, i.e. I(λ) = 0,01 · I0(λ), we can simplify (3):
This function d(λ) is our graph of light penetration into seawater, which is pictured in Fig. 2. Using this graph we can determine light adsorption in seawater as a function of wavelength K(λ):
K(λ) = 0.99 / d(λ) (4)
By substituting the expression (4) into (2), we can derive the spectral distribution of light at a given depth D:
I(λ) = I0(λ) · (1 - 0.99 · D / d(λ)) (5)
where I0(λ) is the light spectrum on the surface and d(λ) is the graph of light penetration into seawater (Fig. 2).


这一大段大意是说：作一个假定：某一深度的下的光强是海水表面光强的百分之一，经过一番推导，得出I(λ) = I0(λ) · (1 - 0.99 · D / d(λ)) (5)
其中：I(λ)是关于波长λ在某一深度下的光强，I(λ)的函数曲线即为某一深度下的光谱图
I0(λ)是在水面上（深度为0米）的光强函数，I(λ)的函数曲线即为水面上的光谱图
D为海水深度
d（λ）为特定波长的光所能穿透海水深度

Using the expression (5) and the data from graphs in Fig. 1 and Fig. 2, we can obtain the diagram of light energy distribution vs. wavelength at a given depth. As an example, on the same graph (Fig. 3) we pictured light's relative spectral distribution at the surface and at the depths of 5m (about 16.4 feet) and 15m (49 feet). Note: 15m is the maximum depth at which we can still find many light-demanding corals in nature. At the depths below 20m, the number of light demanding species sharply decreases.
使用表达式（5）及图1和图2图的数据，我们得到特定深度下波长与获取光能的关系图。作为一个例子，在同一张图（图3）我们绘制光在表面和在5m深处（约16.4英尺）和15米（49英尺）的相对光谱分布图。注：15m是我们仍能找到许多对光有苛刻要求的珊瑚在自然界的最大深度。在深度低于20m，需光物种数量急剧下降。


Fig. 3 Light spectral distribution vs. wavelength on the surface (light blue), at 5m (blue) and 15m (dark blue) depths
图3 在水面上的（浅蓝色）光谱分布图，在5m（蓝色）和15m深度（深蓝色）光谱分布图



The light-blue graph corresponds to irradiation on the surface, the blue graph - to 5m depth, and the dark-blue - to 15m depth. Note that with depth, the red part of the spectrum virtually disappears.
图3 在水面上的（浅蓝色）光谱分布图，在5m（蓝色）和15m深度（深蓝色）光谱分布图
淡蓝色的图对应的水面上光谱分布，5m深度是蓝图光谱分布，深蓝色是15m深度光谱分布。注意在深水中，光谱中的红色部分几乎消失。
During hundreds of millions years of evolution marine photosynthetic organisms adapted to best utilize mainly the violet and blue parts of the spectrum, which is more abundant in their environment, and are not very sensitive to the red spectrum (which, in contrast, is most actively utilized by terrestrial plants). Symbiotic zooxanthellae in marine photosynthetic organisms are primitive Pyrrophyta algae [5] containing mainly chlorophyll a and c and carotenoid pigments (peridinine, xanthins, etc) which exhibit strong absorption in the blue-green part of the spectrum. [6,7,22]. Fig. 4 [22] demonstrates light adsorption by zooxanthellae.

在数百万年进化中，海洋光合生物形成了主要使用光谱段中紫光和蓝光（这些光在水中更充足）的适应性，而对红光不太敏感（而红光被陆地植物最大化的利用）。海洋光合生物共生藻是原始的Pyrrophyta algae[ 5 ]，它含有叶绿素A和C 并且是 Carotenoid的主要色素成分（peridinine，xanthins等），Carotenoid在蓝绿色光谱段具有极强的吸收能力。[ 6,7,22 ]。（译者注：吸收能力强的波段会形成峰值）
   
Fig. 4 Light absorption by zooxanthellae
图4 [ 22 ]共生藻吸收光分布图。


The horizontal axis is the wavelength, in nanometers, and vertical axis is adsorption, in arbitrary units. You can see from the graph that violet and blue colors strongly prevail over red (note that for red spectrum, the 660-680nm range is preferable).
水平轴是波长，单位nm，纵轴是吸附能力，为相对单位。可以从图中看到，紫色和蓝色段要远多于红色（注意红色光谱的范围，660-680nm段较多）。
Our main conclusion from the above is that violet and blue light are most important for marine photosynthetic organisms.
我们从以上得出的主要结论是，紫色和蓝色光的海洋对光合生物最重要。

田贝贝

mynameismo

二、珊瑚显色的成因—色素蛋白
Knowing what is naturally available to corals from the color spectrum, we shall now consider the next important issue: how irradiation by different spectral ranges affects coral coloration?
知道了自然状态下什么颜色的光谱是对珊瑚有用的，我们现在应当考虑的一个重要问题：如何通过不同的光谱范围辐射会影响珊瑚的颜色？

Before we consider the influence of the light spectrum on coral coloration I would like to point out that even coloration of the same coral may vary significantly depending on conditions. Unfortunately, it is very difficult to provide exactly identical conditions for the corals, even in the same aquarium - and this is even harder for two different tanks. Without providing the right conditions for the corals, other attempts to improve their coloration, such as adjustments of the light spectrum, will be in vain.
在我们考虑什么光波段会对珊瑚颜色造成影响前，我想指出，即使颜色相同的珊瑚其显色性也取决于具体条件。然而，即使在相同的缸中也很难为珊瑚提供完全相同的条件，更别说是两个不同的缸。如果没有给珊瑚提供合适的条件，其他试图改善他们颜色的方法将是徒劳的（例如光谱的调整）。
Experienced reef keepers well know how variable the coloration of the same coral can be in different conditions. There are three main factors which affect it most: light spectrum and intensity, the amount of food available in water (although coral polyps receive a significant portion of their energy from the zooxanthellae, they are also able to capture food particles from the water column), and from the purity of the water. This last factor is easiest to control: techniques to maintain pristine water in reef aquaria are well known. The second factor, too, can be solved easily since there are a number of quality coral foods readily available on the market. At the same time many aquarists believe that, if there are fish living in a reef aquarium, corals will get sufficient food from small particles which float around from feeding the fish (and fish poo too is consumed by corals).
有经验的海缸玩家都知道在不同的条件下，相同珊瑚的颜色会发生极大的变化。最具影响的有三个主要因素：光光谱和强度，水中可用的食物的量（虽然珊瑚接收很大一部分能量来自虫黄藻，但它们也可以从水体中捕获食物颗粒） ，以及水质。最后一个因素是最容易控制的：水族箱中保持水质是众所周知的。第二个因素，也可以很容易地解决，因为市面上有许多高质量的珊瑚食品。同时，许多鱼友认为，如果缸中生活有观赏鱼，珊瑚也会得到足够的食物，因为喂鱼会产生漂浮的小颗粒（并且鱼便便也被珊瑚消耗）。
Light is the last important factor required for good health and the coloration of corals, and yet has not been studied sufficiently well in reef keeping.
光线是使珊瑚状态健康及显色的最后一个重要的因素，但迄今为止光的因素在珊瑚饲养方面没有得到充分的研究。

The situation is rather complex though, since corals can be very variable, and even the same species may contain different chromoproteins (proteins responsible for coloration) - their type and amount are also determined genetically, in the same way as, say, the color of human's eyes. Many of these proteins are fluorescent; i.e., they adsorb the light of a certain wavelength and radiate a different wavelength.
由于珊瑚的多样性，虽然情况相当复杂；而且即使是同一种类的珊瑚也可能含有不同的显色蛋白（蛋白质负责显色），其类型和量也由基因决定，就像人类眼睛的颜色也是由基因决定一样。许多这些蛋白质的是荧光的，即，它们吸收一定波长的光，并辐射出不同波长的光。



Fig. 5 shows four specimens of the same species, Acropora millepora, in which different chromoproteins prevail:
图。5示出了四个相同品种的鹿角珊瑚（Acropora millepora）的样本，其中不同的色蛋白占据了主导地位：
Fig. 5 The Acropora millepora specimens with different prevailing chromoproteins: (A) low concentration of chromoproteins, the color of zooxanthellae dominates; (B) green fluorescent proteins; (C) red fluorescent proteins; (D) non-fluorescent chromoproteins. Image courtesy of Dr. C. D'Angelo and Dr. J. Wiedenmann, University of Southampton, UK, Coral Magazine, Nov./Dec. 2011
图5中鹿角两天样本有不同的主导显色蛋白：（A）色素蛋白浓度低;，虫黄藻的颜色占主导地位（B）绿色荧光蛋白; （C）红色荧光蛋白; （D）非荧光色蛋白。图片出处：Dr. C. D'Angelo and Dr. J. Wiedenmann, University of Southampton, UK, Coral Magazine, Nov./Dec. 2011


Fluorescence is witnessed not only in hard corals but, for example, in Zoanthidae and Palythoya polyps which exhibit much brighter coloration when irradiated with so-called short-wavelength "actinic" light.
荧光色不仅在硬骨珊瑚中可见，同样，在例如纽扣和Palythoya polyps中也可见，即在所谓的短波长光照射下会表现出更亮的颜色。

bzone3

应该注明是从水族驿站转来的

风雨笑红尘

太长了……

zhangzheng

感谢楼主

小蝙蝠

收藏， 慢慢看。

哈尔滨之光

    谢谢，学习了
来自:IOS客户端

小天

看了第三遍，还没下手灯泡。而且越看越不知道如何下手，科瑞的好且贵。而且没有国产的光谱明确。国产的，标注明确就怕产品不到位。纠结啊

tiandiao

太好了，感谢楼主。

mynameismo

小天 发表于 2015-5-14 16:27
看了第三遍，还没下手灯泡。而且越看越不知道如何下手，科瑞的好且贵。而且没有国产的光谱明确。国产的，标 ...

cree的是挺贵的，文章只是讲了一个方向，具体怎么配置还是得实践

mynameismo

三、人眼的视觉特性
Coral fluorescence is very beautiful but it is not always easy to observe it. Have a look at the luminous function (spectral sensitivity chart) of the human eye (Fig. 6). Light sensitive elements of the eye are represented by two cell types - the so-called retinal cones and rods. The first are responsible for distinguishing between colors, and the second - for grey tones. The cones work best during daytime, the rods - at night. Remember the saying "all cats are grey in the dark." This is just because we mainly see with the rods in the dark, rather than with cones. The rods do not distinguish between colors: they only sense the relative brightness of an object. The rods are most sensitive to the emerald-green part of the spectrum, with the wavelength of about 510nm (of course, when seeing by the rods, this light is only perceived as a brighter shade of gray rather than green.
珊瑚的荧光色是很漂亮，但它并不总是很容易观察到的。（图6）是人眼具有的视光特性（光谱灵敏度图）。眼睛的光敏元件由两种细胞类型来完成-所谓视网膜锥细胞（cones）和棒细胞（rods）。第一种负责区分颜色，第二种为辨别灰色的色调(译者注：辨别明暗)。视锥细胞主要胜任在白天工作，而棒细胞则在晚上。有一个法：“所有在黑暗中的猫都是灰色的。”这是因为在黑暗中辨别颜色的锥细胞对颜色不敏感，此时主要是棒细胞工作，而棒细胞不作颜色区分：它们只感测物体的相对亮度。棒细胞对翡翠绿色部分的光谱最为敏感，约在510nm处（当然，通过棒细胞看时，这个光仅仅看作是不同明暗的灰色，而不是亮绿色的波长。
There are three cell types in cones, each sensitive to a specific part of the spectrum. S-type cones are sensitive to violet and blue (S stands for Short wavelengths), M-type - for green and yellow (Medium wavelengths), and L-type - for orange and red (Long wavelengths). These three cone types, (along with the rods that are sensitive in the emerald-green part of the spectrum) are responsible for color vision in humans. The rods contain a color-sensitive pigment, rhodopsin, and their spectral characteristic depends on lighting conditions. For weak light, rhodopsin's adsorption peak is at about 510nm (the spectrum of the sky at twilight). And therefore the rods are responsible for twilight vision, when colors are hard to distinguish. At higher levels of illumination rhodopsin photo bleaches, and its sensitivity decreases, while the adsorption peak shifts into the blue region. As a result, under sufficient light, the human eye can use the rods as a shortwave (blue) light detector. S-cells are sensitive in the 400-500nm range with a maximum at 420-440nm; M-cells are sensitive in 460-630nm range, with a maximum at 534-555nm; L-cells are sensitive in the 500-700nm range with a maximum at 564-580nm [1]. Sensitivity ranges of long- and medium-wavelength cones are wide and overlapping. Therefore it is wrong to think that certain cone types only react to certain colors - they just more actively react to certain colors than to others [2]. The human eye is most sensitive in the range where sensitivities of M- and L-type cones add up: at 555nm (yellow-green light). The overall spectral sensitivity function [3] of human eye receptors is shown in Fig. 6:
有三种类型的锥细胞，每种对光谱中的特定部分较为敏感。 S型锥细胞对紫色和蓝色敏感（S代表短short的波长），M型 - 对绿色和黄色（中等middle波长），L型为橙色和红色（长long波长）。这三种类型的锥细胞连同对翡翠绿色敏感的棒细胞一起负责人类的色觉。所述棒细胞包含一种对颜色敏感的色素，视紫红质（rhodopsin），并且它们的光谱吸收特性依赖于照明条件。（译者注：光谱吸收特性决定了视紫红质对什么样的光敏感）。微弱光照条件下，视紫红质的吸收峰在约510nm处（天空在黄昏的频谱-译者注：510nm为蓝色，此处黄昏指天空尚未全黑前，并非夕阳西下）。因此在弱光条件下当颜色难以分辨时，棒细胞负责“黄昏视觉”（译者注：在弱光条件下既负责感光也负责辨别颜色。在光强变得更高时视紫红质变浅了（漂白了），以至它的灵敏度降低，而吸附峰移入了蓝色域。其结果是，在足够的光照条件下，人眼可以使用杆细胞作为短波（蓝色）的光检测器。（译者注：此处作者表达得不是非常清楚，欲深入研究可搜索：视细胞，视紫红质，暗视觉） S-细胞是在400-500nm的范围内最为敏感，而最大吸收值420-440nm; M-细胞在460-630nm范围敏感，最大在534-555nm; L细胞对564-580nm敏感在500-700nm范围内具有最大吸收值[1]。L细胞和M细胞的灵敏度范围是重叠的。因此，有人错误的认为某些类型的锥细胞只对应某些颜色，实际上它们只是对某些颜色更敏感。人眼对M细胞和和L细胞重叠的区域的光谱最为敏感：为555nm（黄绿色光）。人眼的整体光灵敏度函数[3]示于图。 6：

6

Fig. 6 Luminous function of the eye
人眼视觉光谱图（译者注：明视觉）
An important conclusion here is that the human eye sensitivity to light depends on the wavelength. For example, radiation of equal power is perceived 27 times brighter for the 555nm wavelength than for 450nm; this difference increases to 57 times for 420nm, and 135 times (!) for 410nm.
这里的一个重要结论是，人眼对光的敏感度取决于波长。例如，相等功率下的辐射被感知555nm的波长的明亮度是450nm的27倍;对于420纳米这种差异会增加至57倍，对410纳米为135倍。
Humans visually perceive any object as the sum of its reflected light and the object's intrinsic emission (an object is considered light emitting if its total emission at a certain wavelength range is higher than the falling light energy in that same region). Usually objects only reflect light, and their color is determined by the ratio, in which different wavelengths falling on its surface are adsorbed or reflected. For example, green leaves adsorb all visible wavelengths except for green, which is reflected - therefore we perceive it as green. When an object not only reflects but also emits its own light, the eye combines the emitted and reflected light spectrum into its perceived color. Yielding color depends on the ratio of the intensities and wavelengths of both reflected and emitted light. This color addition is best illustrated by the diagram shown in Fig. 7:
人类视觉的感知是通过感知对象反射光的与其自身固有发光的总合（如果一个物体在一定的波长范围内的总光能释放量高于在同一区域的吸收量则被认为是发光）。一般的对象只反射光线，而它们的颜色是由其吸收光及反射的光的比例所确定。例如，绿色的叶子吸收除了绿色外所有波长的可见光，因此，我们认为它是绿色的。当对象不仅反射光，而且自身也发光时，眼睛结合了发射和自身发光的光谱构成其感知的颜色，产生颜色取决于两者的光强和波长的比率。这种颜色加成在图中得以体现。 7：

7

Fig. 7 Additive color mixing
颜色合成图

When looking at the computer monitor, you witness the effects illustrated by this chart: every pixel on the screen consists of three sub pixels: red, green and blue, and all colors are obtained by combination of their intensities.
当注视电脑显示器时，你可以看到该图的具体体现：电脑屏幕上的每个像素包括三个子像素：红色，绿色和蓝色，所有的颜色是由其强度组合而成的。
Note that pure purple color and its tints, such as magenta or fuchsia, are unique in being non-spectral or extra-spectral: there is no specific wavelength associated with these colors, they are mixtures, and one of the required components is violet, with the wavelength around 400nm [13], and red. If a specific light source has no radiation in this range, up to 20% of the whole color palette is lost - and these are very bright colors and their shades! It is also interesting to note that by combining the yellow and blue colors the resulting color is visually perceived as pure white.
需要注意的是纯紫色及其相关染料是很独特的，例如如酱紫色（magenta）或紫红色，它们在非光谱或超光谱中才能找到：没有与这些颜色相关的特定波长，他们是合成出来的，所需的合成材料之一是约400nm[13]的紫，和红色的波长。如果一个特定的光源在不能发出此范围内的光，那么达到了整个调色板20％的颜色会损失掉 - 而这些都是非常鲜艳的色彩！同时在图中你会注意到，通过组合黄，蓝颜色产生的颜色在视觉上感知为纯白色。
Color vision is mainly inherited genetically. We are not talking about the defects of color vision, such as color blindness - but each person perceives colors in his own way, and this difference can be very significant. Apparently, it is very important to be able to adjust the spectral distribution of the light fixture, to find an individually suitable color distribution in the reef tank.
对颜色的感知力（色觉）主要是遗传基因决定的。即便我们不考虑色觉的缺陷，如色盲 - 但每个人对颜色有都自己的感知，这种差异可能会非常显著。当然，我们仍希望能够调整发光装置的光谱分布，以找到在水族箱合适的颜色组合。

mynameismo

四、珊瑚的荧光发色特性
To watch coral fluorescence we shall irradiate the fluorescent proteins with light of a specific wavelength. Look at the adsorption and radiation wavelengths chart for most common fluorescent pigments available in marine organisms [9], shown in Fig. 8:
图8展示的是几种海洋生物中中最常见的荧光色素[9]，它们对特定波长的吸收有图中展示的激发特性


Fig. 8 Adsorption and emission wavelengths for fluorescent pigments available in marine organisms. The figure is courtesy of Dan Kelley
图8 荧光色素吸收-激发特性

The horizontal axis are the wavelengths which cause fluorescence in various chromoproteins; the vertical axis is the wavelength emitted as a result of fluorescence. You can see that virtually all pigments adsorb shorter wavelengths and emit longer wavelengths. As we have shown above, the eye is most susceptible to the 550nm range, and the closer the emitted light is to that wavelength, the brighter it will be perceived. Thus, specific proteins available in marine organisms adsorb the poorly visible to the eye short wavelengths and fluoresce with a color which looks much brighter to our eye. Under purely "actinic" light, which only contains shorter wavelengths, our fish tank will glow with bright colors, whereas the light from the fixture itself is almost invisible to the eye. This gives the impression of miniature light bulbs installed in each coral or polyp, which glow brightly in the dark!
横轴是导致荧光蛋白能显色的光波长;纵轴是所激发出荧光的波长。你可以看到，几乎所有的色素吸收波长较短而发出的波长更长。正如我们在上文所示，肉眼最敏感的光谱段在550nm的范围内，所以更靠近550nm的发射光更亮更易被察觉。因此，在海洋生物利用特定蛋白质吸收肉眼不太敏感的短波长光并发出更亮的荧光。在只有的“光化学”灯照射下（actinic light），灯只包含肉眼几乎是看不见的极短波长的光，而我们的鱼缸会发出鲜艳的荧光，就仿佛在每个珊瑚上安装了小灯泡一样！
Color of a coral, as perceived by the eye, also depends on the color of falling light. The color of any object that we see represents the reflected portion of the falling light spectrum. As we have pointed out above, when illuminated by a full-spectrum light, the leaves of most terrestrial plants adsorb almost all parts of the visible spectrum, and reflect the green part - therefore we perceive them as green. However, if we irradiate the leaves by a light in which the green part of the spectrum is missing - by red light, for example - they will seem black to us, because all falling light is adsorbed. In a similar manner, white object looks white under full spectral light, because it uniformly reflects all parts of the spectrum, but will "take up" the color of any light that we throw at it: red, green, blue, or their combination.
肉眼所见的珊瑚的颜色也取决于接收光的颜色。我们所看到的任何物体的颜色体现了接收到的光谱的反射部分。正如上文指出，当由全光谱光照射，大多数陆地植物的叶子吸收可见光谱的几乎所有部分，并反射绿色部分 - 因此，我们认为它们为绿色。然而，如果我们用缺失绿色光谱段的光照射的叶子 – 例如红色光 – 那对我们来说叶子会是黑色的，因为所有落入光被吸收。以类似的方式，白色物体看起来在全光谱的白光，因为它统统反射了全光谱的所有部分，但会呈现我们扔给它的任何颜色（红，绿，蓝，或它们的组合）。（译者注：此次take up语意不明）
Back to corals - let us consider an organism containing a protein which, when irradiated by the 420nm light, will fluoresce by the 520nm wavelength. For reasons of simplicity, suppose that our light source radiates only at the 420nm wavelength, and the coral adsorbs this light completely, without reflection. The human eye has extremely low sensitivity to this wavelength (almost invisible), whereas it is most sensitive to the wavelength radiated by the coral as a result of fluorescence. We shall see this fluorescence very well in the "dark" pure actinic light. If the light source includes radiation at other wavelengths, the resulting color of the marine organism will be added up from fluorescence and reflected light. If the light source contains wavelengths, to which the eye is very sensitive (especially in close proximity to the 550nm sensitivity peak), we will mainly see the light from the fixture, and perception of coral fluorescence will be weak on this bright background.
回到珊瑚上来，我们考虑某种荧光蛋白，当受到420nm波长的光照射时会发射出520纳米波长的光。为简单起见，假设我们的光源发射仅在420nm波长处，并且珊瑚完全吸附该光而不发生反射。人眼对该波段具有非常低的敏感性（以至几乎不可见），而该波段恰是激发珊瑚荧光的峰值波长。在“黑暗”纯光化灯的光线下我们将能很容易的看到这个荧光。如果光源包括其它波长，那么生物的所呈现的颜色将由发射的荧光和反射光相加。如果光源包含肉眼非常敏感的（特别是在靠近550nm的灵敏度峰值）波长，我们将主要感受灯发出的光，而在此明亮背景下我们感知到的珊瑚荧光将很弱。
Our conclusion is that for best observation of fluorescence, we shall illuminate the tank with such light that its reflected portion would least hinder us in seeing the light radiated by corals. Wavelengths required for fluorescence of all chromoproteins are numerous, and there is no single wavelength that could be used for making an ideal actinic light. Based on Fig. 8, fluorescence is observed in quite wide a range of falling light wavelengths, mainly between 400 and 500nm, and different organisms have different fluorescent protein sets. For best fluorescence we need the capacity to adjust the light spectrum in the 400 to 500nm range, according to the needs of a particular aquarium.
我们的结论是，要想最好的观察到荧光，我们将选择那些所在光谱段能最小限度的妨碍我们看到珊瑚荧光的光用于照明。要想激发所有的荧光蛋白发色所需的光谱是段是很宽的，所以没有单一波长的光源可以用来制作一个理想的光化灯。基于图。 8，荧光会被相当宽的范围内的光的所激发（主要是400至500纳米），并且不同的生物有不同的荧光蛋白集。为了最好的荧光效果，我们需要调整的光谱在400〜500nm的范围内，根据特定的水族馆的需要。
Note that the strongest fluorescence will be observed in 400-450nm range, particularly because the eye sensitivity in that range is very low. The light in this range is usually called "actinic light."
需要注意的是最强的荧光将在400-450 nm范围内可观察到的，特别是因为在这个范围内的眼睛的灵敏度非常低。在此范围内的光，通常被称为“光化光”。
Surely, coral fluorescence is one of the main factors to provide a reef tank's beauty, but the light in the 400-500nm range also has other importance: it is the most optimal light to promote marine photosynthesis. Therefore this part of the spectrum is of utmost importance for a reef tank.
当然，珊瑚荧光是造就一个美缸的主要因素，此外400-500纳米范围内的光也有其他的意义：它是促进海洋光合作用最理想的光源。因此，这部分的频谱对于水族箱至关重要。
This conclusion matches well with the experimental research in this field [16]. Fragments of Acropora millepora colony were maintained for six weeks under comparable amounts of red, green, and blue light. The conclusion of the article is that "the enhancement of coral pigmentation is primarily dependent on the blue component of the spectrum and regulated at the transcriptional level," and "light-driven accumulation of GFP-like proteins observed upon green light exposure is likely due to residual blue light passing the green filter." The experiments also revealed that radiation in the 430nm range is most efficient in promoting the protective bright coloration of the corals:"Among the known FPs and CPs, only the absorption properties of CFPs spectrally match the major absorption band of chlorophyll a and c at ~430 nm, making them suitable for effective shielding of the photosynthetic system of the zooxanthellae."
这一结论（译者注：400-500nm很重要）在珊瑚领域研究中 [16]得到印证。的鹿角在等光强下的红色，绿色，和蓝色光照射下饲养六个星期。文章的结论是，“珊瑚色素沉淀的增强，主要是依赖于光谱的蓝色分量上及其在基因转录水平上的调控，”并说明“在GFP蛋白质（译者注：GFP：绿色荧光蛋白，green fluorescent protein）上累积的光驱动影响（light-driven）可能是由于残余的蓝色光通过绿色隔离层引起的“。实验还发现，辐射在430纳米范围内最有效地促进生成亮色珊瑚保护层：“在已知的FP和CP（译者注：FP荧光蛋白fluorescent protein，CP色素蛋白 chromoprotein），只有CFP(译者注：CFP，青色荧光蛋白cyan fluorescent protein) 吸收光谱特性与叶绿素a和c的主要吸收带（约为430nm）相匹配，这使得它们能有效保护虫黄藻的光合系统。“

mynameismo

五、光强对于珊瑚显色的影响
The intensity of light is also very important for growth and active production of fluorescent chromoproteins.
光的强度对荧光色素蛋白产生也很重要。
A light source could be best characterized, perhaps, by spectral distribution of the optical radiation energy at different wavelengths. This characteristic is usually represented by the spectral curve. For most common light sources, however, the spectral characteristic is usually unavailable, and instead an estimated light flux is provided, in lumens.
光谱分布图最能体现光源的特征。这种特性通常是由光谱曲线来表示。然而，对于最普通的光源来说光谱特性通常是不可知的，我们只能估计光通量，以流明为单位。
Light flux in lumens is the visible light radiation power, as perceived by the human eye - depending on the eye's sensitivity to different wavelengths. Note: One lumen is the total luminous flux emitted uniformly by a light source with luminous intensity of one candela across a solid angle of one steradian (a cone with the angle of approximately 65.5° at the apex). Candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of 555nm wavelength (i.e. the wavelength at the peak sensitivity of the human eye), and has a radiant intensity in that direction of 1/683 watt per steradian.
光通量以流明为衡量可见光辐射功率的指标，然而作为人眼来对不同的波长的敏感度是不一样的。然后说了注明的定义：blabla，卡德卡的定义：blabla
One watt of optical power radiated at the 555nm wavelength corresponds to 683 lm. For any other wavelengths, it is equal to the optical power emitted at that wavelength multiplied by the luminosity function of the eye for the same wavelength. To determine total lumens emitted by a light source we need to sum up the lumens for all emitted wavelengths.
辐射强度为一视觉瓦的波长为555nm的光相当于683流明。计算其他波长的光功率时则需要进行换算，方法是乘以发光度函数而得该波长下的流明值。而总流明需要把所有发射波长的光源发出的总流明相加。
It is evident that the intensity equal light energy in various parts of the spectrum will be perceived differently by the eye: a powerful source in the 400-450nm range will be perceived as very dim light, and a light source emitting in the infrared region will seem black. Therefore an estimate of the light flux in lumens is only valid when light's spectral distribution is unimportant and the only thing that matters is brightness, as perceived by the eye.
显而易见的是，同等强度的光能量而波长不同的光将被眼睛的感知程度是不同的：在400-450纳米范围内的光能量很强的光源会被感知为非常暗的光，而在红外区的光源则会变成黑色。因此，当不考虑光谱分布，而只关心对于肉眼感知的光亮度时，光通量的估计（译者注：光通量估计，即照度测试）才是有意义的。
In our case, a more appropriate parameter for determination of light radiation would be the number of photons per second, falling on each meter square: μmol·photons/m2/s.
而我们的所考虑的用于测定的光辐射更合适的参数是每秒的光子数，即每秒落在每平方米范围内的光子数，单位：微摩尔·光子/平方米/秒。
During the hundreds of millions years of evolution marine photosynthetic organisms adapted to different light power levels. For each photosynthetic organism three threshold values can be defined [14]. First (least intensive) determines the minimum light required for the maintenance of photosynthetic organism's biomass - it is the minimum required light which will not result in gain or loss of mass. The second threshold value concerns illumination at which the photosynthesis efficiency is highest. And finally the third, upper threshold is the maximum light which can be utilized -there is no improvement in photosynthesis rate above that threshold. These three thresholds, of course, depend on particular organisms, but we can use an estimate for marine photosynthetic organisms living in shallow waters. We can safely call 80-100 μmol·photons/m2/s low light, 150-200 - medium, and 300-400 - optimal. The saturation limit of photosynthesis is about 600-700μmol·photons/m2/s.
在亿万年的时间里海洋光合生物适应了不同的光功率水平。我们可以给每个光合生物体定义3个阈值[14]。第一个值（最低强度）定义为光合生物所需的最低光 - 它是所需要的最小光，不会导致增益或质量损失。第二阈值定义为其光合作用效率最高值。第三个值，是光合作用所能利用的最大光值。当然，对于特定的生物，这三个阈值是不同的，但我们可以设定一个估计值适用于生活在浅水水域的海洋光合生物。我们可以设定80-100微摩尔·光子/平方米/ 秒为低光，数值150-200 为中光强，数值300-400 为最合适的光强。光合作用的饱和极限为约600-700μmol·光子/平方米/秒。
In our reef tank, we shall achieve a significantly better illumination than the minimum threshold - preferably near the optimal threshold.
在我们的水族箱中，我们将努力营造光强大大高于最低阈值的照明 - 最好是接近最优的阈值的照明。
Let us consider yet another experiment with Acropora millepora to illustrate the production of chromo proteins under less than optimal illumination, and when the light level is in optimal value for the species (Fig.9).
我们看看另一个实验，图9展示了鹿角珊瑚在低于最适光强下以及在最适光强下所生成色素蛋白的情况。

9

Fig.9 An experiment with Acropora millepora illustrating the production of chromo proteins insufficient for photosynthesis, and intensity for optimal illumination for this species.
图9，鹿角珊瑚在光强不足及光强适当时色素蛋白生成情况

Regarding light intensity this work also states that chromo proteins are not formed under illumination levels below 100 μmol·photons/m2·s, and their number grows almost linearly along with the increase of light intensity up to about 700 μmol·photons/m2·s.
However, it is not always a good idea to provide as much light in home aquaria, since a coral can become very demanding to its environment parameters under such high levels of illumination. Under less than perfect conditions such high levels of illumination can yield a contrary result: coral bleaching.
关于光强方面还应指出，染色体蛋白质在低于100微摩尔·光子/平方米·秒的光强度情况下是不会生长的；而当光照强度增加至约700微摩尔·光子/平方米·秒时，色蛋白数量几乎随着光照强度呈线性增长
然而，为水族箱中提供尽可能多的光并不总是一个好主意，过高的光强会使珊瑚变得对环境要求非常的苛刻。在不完美的环境条件下，高照明可能产生反作用：珊瑚白化。
The experiment illustrates that optimal light levels improve coral growth and coloration, both for ordinary and fluorescent chromoproteins.
实验表明最佳的光照水平有助于珊瑚的生长并使其显色（无论是普通色素蛋白还是荧光色素蛋白）。

海水小虾

顶一个，学习了

泡泡

非常深入，还有吗，期待更新

来自:Android客户端
四川省德阳市广汉市成渝环线高速公路

mynameismo

5imax 发表于 2015-4-17 18:39
非常深入，还有吗，期待更新

来自:Android客户端

还有，有空了慢慢译

熊和鱼

帮顶，虽然看的晕头转向。嘿嘿

bzone3

哦 原来你这个文章是把advancedaquarist原始文章重新翻译了一遍啊 虽然水族驿站的8z两年前翻译过了 但是你重新翻译还是算原创的 很令人钦佩

mynameismo

bzone3 发表于 2015-4-17 19:51
哦 原来你这个文章是把advancedaquarist原始文章重新翻译了一遍啊 虽然水族驿站的8z两年前翻译过了 但是你 ...

是吗，哪能找到，害我译得这么辛苦。有几个地方我还想对比核对一下，在此贴链接违规的话PM一下吧

mynameismo

六、LED的优势

Concluding from the above, light in the 400-500nm range is most beneficial for marine photosynthetic organisms, and its shortwave portion (400-450nm) is most useful for their bright coloration.
从以上结论得出，400-500 nm范围内的光是最有利于海洋光合生物的，其短波部分（400-450 nm）为对珊瑚显色最有用。

Let us consider the most popular actinic light sources for a reef tank. These are mostly fluorescent bulbs which mainly radiate in the 400-500nm range, such as Giesemann Actinic Plus, Fig. 10:
让我们看看最流行的的水族箱光源，大多采用的是主要辐射在400-500nm范围内荧光灯，如Giesemann Actinic Plus，图10：



Fig. 10 A typical actinic fluorescent tube: Giesemann Actinic Plus
图10 Giesemann Actinic Plus 荧光灯

Looking at the spectral distribution of this bulb we can see that apart from the pure actinic spectrum, which is required for coral fluorescence, there are also distinct "parasitic" peaks around 550nm. As we have pointed out, the human eye is over 20 times more sensitive to the wavelengths in this range rather than to the "actinic" range which causes fluorescence (see Fig. 6).
由这个灯泡的光谱我们可以看到，除了能使珊瑚发出荧光的纯光化光谱波段，在550nm附近还有独特的尖峰。正如我们先前所指出的那样，人类的眼睛在这一波长范围内（550nm附近）比其它波段要敏感20倍以上，而人眼在导致荧光的“光化”范围内是不敏感的（参照图6）。
As a result, this bulb is visually perceived as quite bright, almost white, but with strong blue-violet tint. The resulting fluorescence will be partially "dimmed" as a result of this parasitic radiation in the well-to-see range.
其结果是，该灯泡会被视觉感知为相当明亮，几乎是白色的，但带有很强的蓝紫色调（译者注：此灯应该属于蓝管灯而不是白管）。而由于肉眼对荧光灯在550nm附近的发出的光线较敏感使得珊瑚产生的荧光在此明亮的背景下将“变暗”。
In recent years multiple attempts were made to create narrow-range "actinic" bulbs. One of the best is Giesemann POWERCHROME actinic plus, with significantly reduced 450-500nm portion (Fig. 11):
经过近年来多次尝试已经创建出窄范围的“光化”灯泡。其中最好的是Giesemann POWERCHROME actinic plus，它显著减少了450-500纳米的部分（图11）：

Fig. 11 The spectrum of the POWERCHROME actinic plus bulb
图11 Giesemann POWERCHROME actinic plus光谱图

We can see that "parasitic" portion of this bulb's spectrum is smaller and the 420-430nm range is better represented. However, this bulb too, still looks quite bright to the eye, because of the still present peak at 550nm. So far, conventional fluorescent tubes are not so efficient for observation of fluorescence in a reef tank.
我们可以看到这个灯泡光谱的“第二峰值（550nm附近）”范围是比较小的，并且420-430 nm范围内有更好地表现。但是，这种灯泡看起来还是相当明亮的，因为在550 nm处仍然存在峰值。到目前为止（译者注：这篇文章是2012年发表的），传统的荧光灯管照明下观察荧光的效果都不是很好。

Desperate? No! Quite recently, there was a breakthrough in the field of solid-state lighting, and many light fixtures for reef tanks are now constructed with the use of LEDs. The advantages of LED fixtures over the conventional light sources are many; we shall only consider the main factors.
听上去是不是令人绝望？好消息！最近在固态照明领域出现了的突破，许多LED灯具用于水族箱照明。LED灯具比常规光源有更多优点，我们只考虑主要方面。
Advantage #1: Higher efficiency and less heat generation
优势一：更高的效能且产生更少的热量
Higher efficiency has two components. First is that LEDs are about twice more efficient than conventional fluorescent tubes or Metal Halide bulbs in converting the electric energy into light. Second is that LEDs only radiate in one direction of the plane and hence are not apt to block their own light. By utilizing proper lenses, LED light can be easily concentrated in the desired region. Good LED lenses are compact in size and, at the same time, can help to transfer up to 90 percent of produced light through the water surface. For comparison, when using conventional bulbs with reflectors usually only 40% of light penetrates the surface. Best reflectors (often cumbersome) can yield up to 60% of light penetration, and the bulb itself partially blocks the light returning from the reflector. Resultant efficiency of best LED fixtures can be three times higher compared with the best light bulbs. Consequently, LEDs can generate over 4.5 times less heat. This practically means that by installing a LED fixture over a reef tank we can probably eliminate the need for an expensive chiller (which also consumes significant power). Thus, LED fixtures may achieve significant power savings; apart from the economic effect, their environmental impact is also significant!).
高效能体现在两个方面。首先，LED的光能转化率（电能转换为光）比常规荧光灯管或金属卤化物灯泡的高大约两倍。此外，发光二极管只在一个平面的一侧辐射，因此不容易阻塞其自己的光。通过利用适当的透镜，LED灯可以轻易将光集中在所希望的区域。好的LED透镜尺寸紧凑，并在同一时间，使达到90％的光到达水面。相较而言，使用反射装置的常规灯泡通常只有40％的光能达到到水面。最好的反射装置（通常很复杂）可产生高达60％达到水面，并且灯泡本身也部分地阻挡了从反射装置返回的光。最佳的LED灯具的转化效率可以是与最好灯泡的三倍以上。因此，LED可以比灯泡减少产生超过4.5倍的热量。这意味着，通过在水族箱安装LED灯具，我们可能可以不必使用昂贵的冷却器（冷却器也非常耗电）。因此，LED灯具可以显著降低功耗;不但有经济价值，对环境的影响也很显著！）。

mynameismo

六、LED的优势(2)
Advantage #2: Extended life cycle
优点2：使用寿命长
As a solid-state light source, a light emitting diode does not have quickly wearing parts, such as an incandescent filament. When operated at or below rated current, and providing that they do not overheat, high quality LEDs degrade very slowly. But LEDs too have their specific needs which have to be considered when designing a fixture.
相较白炽丝，LED元件不会迅速损坏。在正不高于额定电流状态下工作时LED不会过热，高品质的LED的降解速度很慢。但是设计LED灯具时也需考虑的其特定需求。
Lifespan of the best LEDs available in the market today (Cree XT-E, LUXEON Rebel ES) is indeed very high, if sufficient heat removal and properly conditioned power are provided. Of course, these are new LEDs and their operation have been tested for tens of years, but using complex models their life term and luminosity drop in that period can be estimated. We shall refer to two types of such forecasts: based on Cree's model (which we call the "worst case scenario" or "pessimistic model"), and in parenthesis we provide figures based on the Philips model for their LUXEON Rebel ES (which we call the "optimistic model"). If all the required operation conditions are fulfilled, we will still be getting about 70% of LED's initial radiation power after 40 (150) thousand hours of operation. These figures translate to 10 (33) years of operation of a light fixture, providing 12 hours of operation daily! After this period the LEDs will continue to lose luminance, reaching about 50% of the initial value after 100 (200) thousand hours!
现在市场最好的LED品牌（Cree XT-E, LUXEON Rebel ES）灯的寿命是非常高的，如果提供足够的散热和正常功率。虽然，这些新型LED需要数十年的时间进行功能测试，但通过复杂的模型我们可以估算生命期限和光衰情况。我们参照两种模型：基于Cree公司的模型（我们称之为“最坏的情况”或“悲观模式”）；与其相对，我们提供了基于飞利浦型号为LUXEON Rebel ES的数据（我们所谓的“乐观模式”）。如果所有必要条件得到满足，我们在最坏情况下在40，000小时（乐观模式下是150，000小时）得到全新LED约70％的光发射功率。这些数字可以转化为10年（33年）的灯具使用寿命（以每天提供12小时照明来计算）。此后的LED将持续光衰。据估计100，000小时后（乐观模式：200，000小时）光强为最初的约50％！
The probability of a single LED failure on a fixture is quite low, about 1% during the period of 50 thousand hours of operation, and after this period the probability increases to 50% by 200 thousand hours. Several LEDs in a light fixture are usually connected in series, and therefore, if one LED dies, the whole string will be effected. If we look at these figures statistically, is likely that for a fixture with about 200 LEDs this can happen in 10 years. However a LED's death is a probabilistic event and it can happen that a particular light emitting diode may get "fried" during the very first hours of its life. In practice, if the conditions are good, lifespan of modern LEDs is quite long.
单个LED发生故障的概率是相当低的，在5万小时内故障率约为1％，并在此之后的故障率会增大：200万小时以上会达到50%。LED灯通常会有多个LED灯珠串联在一起，因此，如果一个LED灯珠坏了，整个串连电路将受影响。利用概率统计学分析，一盏大约有200 颗灯珠的LED灯其发生灯珠损坏的可能性为10年。当然，一个LED灯珠损坏是一个概率事件，某些发光二极管也存在刚出厂就“挂彩”的情况。实际上，如果条件得当，现代的LED的寿命是很长的。
In comparison, conventional fluorescent tubes need to be replaced once every four to six months. Based on our worst case scenario, it means that they will have to be replaced at least 20 times during the lifetime of a LED fixture. Providing that the cost of specialized tubes for reef lighting can be quite high, a LED fixture can provide significant savings; e.g., not only monetary, but also of the time that was to be spent for acquisition and replacement of light bulbs.
相比较而言，传统的荧光灯管需要每四到六个月更换一次。而即使在最坏的情况下，LED灯能长时间不用更换，时间是传统荧光灯的20倍。考虑到专业的礁岩缸照明成本是相当高的，一个LED灯具能提供显著的节省空间:不仅对于LED装置本身，也体现在灯泡的更换成本。
Let us try to calculate the possible savings from using a LED fixture. A 300W LED fixture can replace a 900W T5 fixture used on a 160 gallon SPS reef tank. In 10 years the LED fixture will save ((900-300)/1000)*12*365*10=26280KWh of electric power. The cost of electricity depends on where you live, how much you use, and possibly when you use it and the rates from the same provider can range from 12c to 50c per kWh [17]. For our estimate we shall use a sample rate of 15c per kWh, which is a reasonable example (you can find out how much you are actually paying for electric power by looking at your bill). Based on the 15c per KWH example, the fixture will save you $3942 in power alone. If we take the average cost of a specialized 80W T5 bulb to be around $25, we shall additionally save $25*10*20=$5000 in bulb replacements. Your total savings in 10 years will be about $8942. This is a "best scenario" estimate and we did not consider many additional expenses - for example, the cost of an aquarium chiller to remove the excessive heat from the tanks, as well as energy costs related to its operation. Besides, there are non-monetary values - such as the comfort of not having to provide maintenance on a light fixture in 10 years! Thus far, direct savings during the operational period are quite a few times higher than the cost of even most expensive LED fixture. In other words, not only you are getting it free, but it will even bring you some profit in its lifetime!
让我们考虑使用LED灯能节省多少钱。对于160加仑SPS水族箱来说，使用300W的LED灯具可以取代900W T5灯。在10年的LED灯具将节省（（900-300）/1000）*12*365*10=26280千瓦时的电力。电力成本取决于你住在哪里，你每天使用多少，并在什么时候使用它，对于同一供电商电费可能在每千瓦时12美分到50美分间变化。我们假设电费为每千瓦时为15美分（你可以通过看你的电费单知道每度电多少钱）。假设每度电15美分，LED灯将为您节省3942美元的电费。如果我们假设一个专用的80W T5灯泡的平均成本是25美元左右，我们将额外节省25 * 10 * 20 = 5000美元的灯泡更换费。你将在10年内节省大约8942美元。这是一个“保守情况”估计，我们没有考虑很多额外的开支 - 例如，水冷的成本以及水冷的电费成本。此外，还有非货币价值 - 比如10年内不用担心灯具维修问题！这能省下甚至比最昂贵的LED灯还多的钱。换言之，不仅你能省下钱，它甚至会为你带来一些利润！
Advantage #3: Ability to adjust illumination and spectrum
优点3：具有调节光谱和光强的性能
When using dimmable drivers, the light emitted by LEDs can be easily adjusted. Aquarists often use special controllers to imitate sunrises and sunsets, similar to natural illumination changes during the day. It is important to note, however, that sunsets and sunrises in the equatorial zone are much quicker compared with higher latitudes, and daytime is equal to night (i.e. there is always a 12 hour photoperiod). Look at the diagram shown in Fig. 12 [20]:
利用可调光驱动器，我们可以很容易地调节LED发光状态。鱼友们经常会使用特殊的控制器模仿日出和日落，类似于白天自然光照的变化。然而要注意的是，日落和日出在赤道区域较高纬度相比要快得多，并且白天的时间等于夜晚（即总共有12个小时的光照周期）。见图12[20]：

Fig. 12 The illustration shows how the time of day (A-E) affects the angle of incoming sunlight. Image courtesy of NASA Earth Observatory
图12 展示不同纬度地区不同时段内光照情况（图片由NASA Earth Observatory提供）

Real irradiance at the surface depends on multiple factors, such as cloudiness, the amount of water vapors in the air, atmospheric turbulence, etc. The insolation measured at the Great Barrier Reef on a typical day is shown in Fig. 13[21].
在物体表面，实际接受到的辐照度取决于多种因素，如混浊的水蒸汽在空气中的量，大气湍流等。图13[21]展示了在大堡礁在典型的一天测量到的日照辐射情况


Fig. 13 Irradiance and solar elevation for September 2, 1998 at One Tree Island, Great Barrier Reef (23°30'S, 152°06'E) (Image courtesy of A. Salih, unpublished data)
太阳辐射强度与日升角度的关系，1998.9.2，大堡礁数据（A. Salih, unpublished提供数据）

Also note that the light is almost fully reflected when the sun rays touch the water surface at small angles. Reflection also depends on the wind speed. These dependences are illustrated by the diagram in Fig. 14 [21].
此外，当太阳入射角度很小时，光线几乎都被水面反射掉了。并且反射程度还受到风速的影响。下图展示了上述因素对光强的影响。见图14


Fig. 14 Reflectance of sunlight in relation to solar radiation. Theoretical and measured percentage of sunlight reflected off a completely smooth water surface in relation to solar elevation (based on calculations of Weinberg, 1976; Grichenko in Weinberg, 1976)
图14，随入射角变化时，反射光相当于入射光线的光强百分比。绿线为理论值，蓝点为平静的水面，红点为波涛汹涌的水面。（数据来源Weinberg, 1976; Grichenko in Weinberg, 1976）

This means that natural illumination under water is not sufficient for photosynthesis until the sun rises approximately 15 degrees over the horizon. In approximately 30 minutes after this the illumination quickly increases to about half of the daily maximum value. Therefore actual photoperiod is about 9 hours. These are the factors an aquarist should consider if he is wishing to replicate natural light cycles.
这意味着，直到太阳在地平线上上升大约15度时，在水中的自然光照才足以用于光合作用，。在此之后，经历大约30分钟的快速上升阶段并达到每日最大值的一半。因此如果希望复制自然光的周期，水族箱中的实际光周期为约9小时。

mynameismo

七、光的色彩特性
Now let us consider important characteristics of light, which are required for our further conclusions.
现在，让我们考虑光的色彩特性，这有助于我们得出进一步的结论..
First such characteristic is CCT - Correlated Color Temperature. CCT of a given light source characterizes the temperature of an absolutely black body that would radiate a similar spectrum. The hotter the black body, the higher will be the CCT and the more blue or "cold" will be the light. As an illustration, sunlight has a yellow tint, whereas blue giants - huge stars with high temperature of the surface: 10000K and above (Sirius, for example) - seem bluish even to the naked eye.
一个衡量光特性的指标是CCT（Correlated Color Temperature）-色温。色温定义如下：blabla..（译者注：色温定义通俗说就是指一个理想的绝对黑体光源，其发出的光为X颜色，该光源的开尔文温度为A开尔文（单位K），那么就说X颜色对应的色温为A）。CCT将更高和更蓝或“冷”将是光。举个栗子，阳光有黄色色调，而蓝巨星 – 其巨大的恒星表面具有高温：色温达到10000K以上（比如天狼星），对肉眼来说它看上去是蓝色的。
Let us compare the radiation spectrums from two different absolute black bodies with different CCTs [10]. The diagrams also indicate the dominating wavelength. Fig. 15 pictures the spectrum of a light source with 5500K CCT, and Fig. 16 - with 6500K CCT:
以下的图展示了两个绝对黑体的辐射光谱图，图15为5500K的色温，图16 -6500K色温：

Fig. 15 The spectrum of a light source with CCT 5500K
图15 5500K色温光谱图

Fig. 16 The spectrum of a light source with 6500K
图16 6500K 色温光谱图


You can see that the dominating wavelength increases with the increase of CCT: it is equal to 444nm for the relatively warm light of the 6500K CCT. For a 8000K CCT bulb the calculated wavelength is about 420nm. Practically speaking, CCTs over 20000K is senseless. However, light bulb manufacturers often "abridge" the spectrum to a particular range of special interest, offering light bulbs with the spectrum similar to the one shown in Fig. 17:
可以看到，随着CCT的增加主导波长逐渐增大：主导波长为444nm的6500K 色温的光看上去相对温暖。对于色温8000K灯泡其主导波长约为420纳米。实际应用上，色温20000K以上是毫无意义的。然而，灯泡制造商通常“删节”部分频谱，而使波段集中在一个特定的范围内，于是我们可以获得如图17展示的光谱：


Fig. 17 The spectrum of the Grassy glow super blue 25000K bulb
图17 Grassy glow super blue 25000K灯泡（译者注：字面意思：超级蓝灯）
Even though the dominating wavelength of this bulb is about 450nm, it has a CCT of 25000K! [11]
尽管主要波段集中在450nm附近，该灯的色温超过25000K
Thus, CCTs cannot be used as a criterion for the comparison of particular light source spectra. Moreover, even high CCT values do not guarantee that we shall get the required "actinic" spectrum.
因此，我们不能使用色温来作为特定光源的光谱的比较标准。高色温值不保证我们会得到所需要的“光化”光谱。
Another important characteristic is CRI - the Color Rendition Index. Unfortunately this term is often interpreted wrongly. It characterizes the influence of light source on the perception of an object's color. This parameter shows how correctly a light source with a particular CCT will deliver the color of an illuminated object, compared with an ideal source - an absolutely black body with the same color temperature. To determine the CRI, a set of 8 standard color samples is illuminated with the source and with the light of a back body with the same color temperature. If none of the samples change their color, CRI is equal to 100. The index reduces in inverse proportion to the number of color changes in samples. It is usually believed that a CRI above 80 is good. It is important to know, however, that CRI is calculated for light sources with a particular color temperature. It is not appropriate to compare a 2700K, 82 CRI light source with a 5000K, 85 CRI source.
另一个重要特性是CRI（the Color Rendition Index） – 色彩再现指数（显色指数，色彩还原度）。不幸的是这个词经常被错误地解释。它衡量了的被某光源照射物体的颜色的被肉眼感知的情况。该指标表明在正确的色温下一个物体的颜色能得到怎样的呈现。确定CRI值时，我们用某一光源与一个与其相同色温的理想绝对黑体光源去照射一组8个标准色样，如果色样在两次照射下颜色没有发生改变，那么CRI为100。而相应地，样本的颜色变化的数目越多的CRI指数降低。通常认为，CRI为80以上还是不错的。需要注意的是CRI需要在同等色温下进行比较，比较2700K，CRI82光源和5000K，CRI85光源的CRI是没有意义的。
Also note that CCT and CRI are only defined for full-spectrum light sources. The CRI of monochromatic light is close to zero, and its CCT cannot be calculated. Look at Fig. 15, Fig. 16 - you can see a wide spectrum, starting near 120nm and finishing around 3000nm. In this whole range a clear maximum is present, and most of energy is radiated in a narrow band of wavelengths. Radiation spectrum of a black body can never have the shape of a narrow-band spike, similar to the spectrum of a monochromatic light source, and therefore, calculation of CCT for such sources makes no sense.
同时还要注意的是CCT和CRI只能定义为全光谱光源的衡量指标。单色光的CRI接近于零，其CCT(色温)也是无法计算。从图15和图16 - 你可以看到从近120 nm到3000纳米段的宽光谱。在这整个范围内很容易看到最大值，且辐射最强的波长存在于窄频带内。绝对黑体辐射的光谱是全光谱，绝不能存在类似于单色光源光谱的具有窄带尖峰的形状。因此，CCT不能用来衡量单色光光源的光谱。
All fluorescent and MH bulbs have a discrete spectrum, whereas sunlight has a continuous spectrum. Discrete spectrum is a result of using a discharge in mercury (and other metal) vapors, with several peaks at different wavelengths, mostly in the ultraviolet range. Phosphors on the bulb convert this radiation into narrow bands of visible light. A discrete spectrum vs. continuous is shown in Fig. 18:
所有的荧光灯和金卤（MH）灯泡都具有有离散频谱，而太阳光具有连续的光谱。离散谱的成因是由于灯泡内的荧光粉转化了汞蒸汽辐射出的光线。汞（和其他金属）蒸汽的辐射光谱具有几个峰值，主要是分布在紫外范围内。荧光粉将这些不连续的贬值转换化为可见光窄带。离散频谱与连续见图18：

Fig. 18 Continuous (above) and discrete (below) spectrum
图18 连续谱与离散谱
The gaps - wavelengths that are missing in a discrete spectrum - mean that certain tints of color cannot be correctly rendered under such illumination and, as a result, the light source will have a low color rendition index (CRI). Of course, light bulb manufacturers try to avoid deep gaps in the spectrum. Look at the spectrums of popular marine MH bulbs: BLV HIT 10000K and BLV HIT 14000K (Fig. 19).
波长中所缺少的部分意味着物体的某些色调将不能被这种光源渲染，其结果，该光源将具有低的彩色再现指数（CRI）。当然，灯泡制造商会设法避免在频谱深出现间隙。以下是很流行的海洋金卤灯泡的光谱：BLV HIT10000K和BLV HIT14000K（图19）。


Fig. 19 The spectrum of Metal Halide bulbs BLV HIT 10000K (a).
图19

Fig. 19 The spectrum of Metal Halide bulbs BLV HIT 14000K (b).
图19

mynameismo

七、光的色彩特性（2）
These bulbs do not have deep gaps in their spectrum, so that the intensity at a certain wavelength would drop to zero, hence both are full-spectrum bulbs and their CRI can be determined. At the same time, they exhibit clear discrete peaks, meaning that when using these bulbs precise color rendition cannot be achieved. Note that bulbs with different CCT: 10,000 Kelvin - 14,000 Kelvin are used in this example. Their main difference is in the significant portion of 400-440nm radiation in the second bulb, whereas the 460nm peak is missing. This is logical and clear: the higher the temperature of an absolutely black body, the more its spectrum would shift into the short wavelength region. Since the 400-450nm range is most important for a reef aquarium, and because, in order to attract the customer, manufacturers often calculate the CCT to satisfy their interests, we can safely state that maximum radiation in the required range is only achieved when a CCT of approximately 20000K is declared. Have a look at the spectrum of a 400W Hamilton Metal Halide bulb with 20000K CCT (Fig. 20):
这些灯泡的光谱不存在间隙，所以不会出现某一特定波长光线的强度突然下降到零的情况。因此，这两者都是全光谱灯泡并且其CRI是可以确定的。与此同时，这两种灯还显示出明显的不连续的峰值，这意味着使用这些灯泡时无法实现精确地色彩还原。需要注意的是灯泡具有不同的色温：例如10,000K及 14000K。它们的主要区别在于，在第二种灯泡在400-440纳米的辐射较为显著，而460nm处峰值缺失。灯泡做出如此设计的合理解释如下：由于随着绝对黑体的温度升高，其频谱将转移到短波区域，而400-450nm波段范围是水族箱照明的关键，并且为吸引顾客制造商通常会提供色温值以满足顾客需求。我们可以肯定的是，要达到所需波段范围内的辐射水平，灯具必需达到约20000K。下图为400W汉密尔顿金卤灯灯泡的光谱色温20000K（图20）：

Fig. 20 The spectrum of a 400W Hamilton Radium Metal Halide bulb with 20000K CCT
图20 400W Hamilton Radium Metal Halide bulb 光谱图

This bulb radiates a significant portion of its power in the 400-450nm range, with a noticeable peak around 420-430nm. Only a small portion of radiated power in the longer wavelength range makes its light visible, rather than dark to the eye as violet-blue.
这种灯泡在400-450 nm范围内具有显著的辐射功率，在420-430纳米附近存在明显峰值。该灯在肉眼敏感的波长范围内只有一小部分的辐射功率，但又不至于太少以至使肉眼只感受到很暗的蓝色。
High CCT bulbs are often characterized by a significant portion of radiation in the 420-430nm range. Experienced reef aquarists recommend 20000K bulbs for providing the best color for marine organisms. This advice, obtained through years of practice, matches well with the conclusions we derived above.
高色温灯泡的特点通常是在420-430纳米范围内具有显著的辐射。经验丰富的鱼友推荐20000K灯泡，能给海洋生物提供最佳颜色。这个建议，通过多年的实践获得的，很好地与我们上面得出的结论相匹配。
Of course, there is an exception from any rule. In our case, such an exception is marine organisms which only live in shallow waters in their natural habitat, in the tidal zone for example. This is an important reservation: there are species which can live both in shallow waters and at medium depth, and they are quite tolerant of the light spectrum. Certain species, however, can only live close to the surface, and cannot survive even at small depths. Such species do not adapt well, not only to the weaker illumination but also to a different spectrum. Certain species of colonial polyps of the Zoantidae genus are an example of this.
当然，任何规则都有例外。这样的就是那些生活浅水水域及潮间带的海洋生物。还一种不确定因素：那些既可以在浅水和又可以在中等深度海水中生活的物种，他们能适应相当宽的光谱。然后某些物种只能生活接近表面，它们甚至不能在稍微有点深的地方生存。这些物种的适应力都不好，不仅不能适应较弱的照明，也为不能适应不同的频谱。某些纽扣属（Zoantidae）的珊瑚就是这样的。
Let us now consider the spectrum radiated by various LEDs. The spectrum of a cool-white LED with CCT around 7000K is shown in Fig. 21.
现在让我们看看各种LED的辐射光谱。图21为冷白色色温7000K左右的LED的光谱。

Fig. 21 The spectrum of a white LED
图21 冷白LED光谱

This spectrum is not discrete, but has a significant sag in the 470-500nm range. This gap can be compensated easily by adding a blue LED to the fixture. Have a look at the spectral power distribution for different color LEDs of Philips LUXEON Rebel ES series (Fig. 22).
该频谱也不是离散的，但在470-500纳米范围内的出现显著的下垂。通过加上蓝色LED，这个间隙可以很容易地来补偿。以下为飞利浦的LUXEON Rebel ES系列不同颜色的LED（图22）的光谱能量分布。

Fig. 22 Spectral power distribution of Philips LUXEON Rebel ES color LEDs
图 22 飞利浦LED光谱
Radiation of the Blue LED is most suitable to compensate for the required 470-490nm range. Even a better match could be achieved by using a LED with a 475nm peak - fortunately, such LEDs exist!
蓝色LED能有效补偿470-490纳米的范围所需的光线。通过使用LED与475牛米的峰值可以实现更精确的匹配！
To better explain this, let us consider the term bin, which manufacturers use to characterize their LEDs. A bin is a group of LEDs that have been selected according to a certain parameter. There are efficiency bins, CCT and CRI bins, and dominating wavelength (DWL) bins are available for monochromatic (single color) LEDs. DWL bins for blue LUXEON Rebel color LEDs are shown in Table 1.
为了更好地说明这一点，厂家用bin来描述他们的LED的特性。Bin是一组具有同同特点参数的LED。例如有能效bin(具有相同的能效参数)，色温bin和CRI bin，而主导波长（DWL）bin可用于单色的LED。 DWL bin蓝色LUXEON Rebel彩色系列LED见表1。

Table 1 LUXEON LED bin distribution by wavelength
表1 波长bin LED
Adding a LED with the DWL bin code 4, we can flatten the white LED's spectral curve in the 430 to 600nm wavelength range.
利用bin code 4的LED，我们能填充白光谱中430到600nm段。

mynameismo

八、LED灯光谱配置
We shall now turn to actual implementation of LED fixtures for the reef aquaria.
现在我们真正进入到水族LED灯具的讨论。
Using just two types of LEDs (white and blue) is not sufficient, because such a fixture will miss a significant amount of light in the 400-450nm range - much less than it is measured in the ocean, at the depth of just a few meters. The 450nm spectral range can be easily scaled up by using Royal Blue LEDs with a corresponding peak. Apart from that, the white LED spectrum quickly diminishes in the dark-red range, around 650-660nm. According to the model shown in Fig. 4, this part of the spectrum is also required for shallow-water photosynthetic organisms and adding this range can be beneficial -it will also help to emphasize the red color in the reef tank. What kind of spectrum shall we attain as a result? Answer: Something very close to the spectrum of the best light fixtures that are commercially available today. As an illustration, Fig. 23 shows the spectrum of Ecotechmarine Radion, ReefBuilders 2011 LED showdown winner [18].
使用只是两种类型（白色和蓝色）的LED是不够的，因为这样的灯具将极大缺失在400-450nm范围内的光照量， -而在只有几米深的浅蓝中，这部分光量是大量存在的。使用宝蓝LED（royal blue）扩展450纳米的光谱范围内的峰值。此外，白色LED的光谱在650-660nm的暗红色范围迅速减弱。根据图4的模型，在浅海生活的光合生物需要这部分光谱，所以加入该波段范围的光是有益的 - 它将有助于突显水族箱中的红色。我们应该使的频谱达到怎样的结果呢？答案是：答案是：某种非常接近目前市面最好的成品灯具的光谱。以下例子是2011年ReefBuilders  展上，Ecotechmarine Radion 的光谱，图23 [18]。

Fig. 23 Output spectrum graph of Ecotechmarine Radion LED fixture
图 23 Ecotechmarine Radion的输出光谱
As you can see, the gap in the 480nm range is properly filled (this fixture uses Cree's blue LEDs). Besides, a small peak in the 660nm range is available. However, any wavelengths in the 400-430nm range, which could promote the fluorescence of many marine organisms, are virtually missing.
可以看到，480纳米范围的波谷被很好地填充了（该灯使用了Cree的蓝色LED）。此外，它还在660纳米范围实现了一个小小的峰值。然而，那些能够提升许多海洋生物荧光效果的400-430纳米波段的光却几乎没有。
This range is missing in the majority of reef LED fixtures. Until recently, no LEDs of proper quality were available in the market for the 420nm range. For the few available offerings the prices were quite high, along with short operation time and poor efficiency. At the same time, the required total radiation in this wavelength range is quite significant, and adding the appropriate number of LEDs seriously affected the total cost of the fixture. As a result, manufacturers installed a tiny fraction of the required number of pure actinic LEDs, at best. In the beginning of 2012 this situation has the potential to change quickly since the introduction of efficient and relatively inexpensive 420nm LEDs [15]. By using these new generation LEDs in pure actinic wavelength range, it is possible to create an affordable LED fixture with proper spectrum required for the reef tank.
这个波段在大多数珊瑚LED灯具上都是缺失的。直到最近，市面上还一直没有品质合适的420纳米范围的LED。一些可以使用但价格都非常高，并且寿命和光效能都很差。另一方面，这个波段需要的总辐射量相当大，加入足够数量的LED会大幅增加灯具的整体价格。于是，生产厂也仅仅安装了极小部分能满足光化需求的LED。2012年开始，情况开始发生飞速变化，因为出现了高效而且比较廉价的420纳米LED[15]。使用这些波长的新一代的LED可以制造既满足珊瑚缸光谱需要而价格也可以承受的LED灯具。
Many hobbyists tried to use inexpensive no-brand Chinese LEDs in the pure actinic range. However, their efficiency is low and, as a result, the crystal deteriorates quickly due to overheating. Worst of all, this deterioration is hard to estimate visually, since the eye's sensitivity in 420nm range is very poor. Besides, spectral distribution of such low-quality LEDs can be very wide (from 350nm in the ultraviolet range, and up to green light): these longer wavelengths affect the visibility of coral fluorescence. At the same time the research conducted by the European Commission Joint Research Center [12] shows that UV light with shorter wavelengths may cause unsightly phosphorescence of small particles suspended in water (Fig. 24).
很多爱好者试着使用廉价的，无品牌的中国制"光化”LED。但是，它们的效能低下，导致的结果是芯片很快地因为过热而衰减。糟糕的是，这种衰减很难用肉眼来估测，因为人眼对于420纳米范围波长极不敏感。此外，这种低品质LED的光谱分布会非常宽（从350纳米的紫外一致延伸到绿色波段）：这些长波会影响珊瑚荧光的可视性。另外，根据European Commission Joint Research Center 的一项研究[12]，较短波长的紫外光会导致水中悬浮颗粒发出影响观赏的磷光(图24)。

Fig. 23 Output spectrum graph of Ecotechmarine Radion LED fixture
图 23 Ecotechmarine Radion的输出光谱
As you can see, the gap in the 480nm range is properly filled (this fixture uses Cree's blue LEDs). Besides, a small peak in the 660nm range is available. However, any wavelengths in the 400-430nm range, which could promote the fluorescence of many marine organisms, are virtually missing.
可以看到，480纳米范围的波谷被很好地填充了（该灯使用了Cree的蓝色LED）。此外，它还在660纳米范围实现了一个小小的峰值。然而，那些能够提升许多海洋生物荧光效果的400-430纳米波段的光却几乎没有。
This range is missing in the majority of reef LED fixtures. Until recently, no LEDs of proper quality were available in the market for the 420nm range. For the few available offerings the prices were quite high, along with short operation time and poor efficiency. At the same time, the required total radiation in this wavelength range is quite significant, and adding the appropriate number of LEDs seriously affected the total cost of the fixture. As a result, manufacturers installed a tiny fraction of the required number of pure actinic LEDs, at best. In the beginning of 2012 this situation has the potential to change quickly since the introduction of efficient and relatively inexpensive 420nm LEDs [15]. By using these new generation LEDs in pure actinic wavelength range, it is possible to create an affordable LED fixture with proper spectrum required for the reef tank.
这个波段在大多数珊瑚LED灯具上都是缺失的。直到最近，市面上还一直没有品质合适的420纳米范围的LED。一些可以使用但价格都非常高，并且寿命和光效能都很差。另一方面，这个波段需要的总辐射量相当大，加入足够数量的LED会大幅增加灯具的整体价格。于是，生产厂也仅仅安装了极小部分能满足光化需求的LED。2012年开始，情况开始发生飞速变化，因为出现了高效而且比较廉价的420纳米LED[15]。使用这些波长的新一代的LED可以制造既满足珊瑚缸光谱需要而价格也可以承受的LED灯具。
Many hobbyists tried to use inexpensive no-brand Chinese LEDs in the pure actinic range. However, their efficiency is low and, as a result, the crystal deteriorates quickly due to overheating. Worst of all, this deterioration is hard to estimate visually, since the eye's sensitivity in 420nm range is very poor. Besides, spectral distribution of such low-quality LEDs can be very wide (from 350nm in the ultraviolet range, and up to green light): these longer wavelengths affect the visibility of coral fluorescence. At the same time the research conducted by the European Commission Joint Research Center [12] shows that UV light with shorter wavelengths may cause unsightly phosphorescence of small particles suspended in water (Fig. 24).
很多爱好者试着使用廉价的，无品牌的中国制"光化”LED。但是，它们的效能低下，导致的结果是芯片很快地因为过热而衰减。糟糕的是，这种衰减很难用肉眼来估测，因为人眼对于420纳米范围波长极不敏感。此外，这种低品质LED的光谱分布会非常宽（从350纳米的紫外一致延伸到绿色波段）：这些长波会影响珊瑚荧光的可视性。另外，根据European Commission Joint Research Center 的一项研究[12]，较短波长的紫外光会导致水中悬浮颗粒发出影响观赏的磷光(图24)。

Fig. 24 Phosphorescence of small particles in water under UV illumination
图24 紫外照明下，水中悬浮颗粒的磷光

The diagram contains several graphs for the phosphorescence of differently sized particles. We are mostly interested in particles sized around 60 μm, which are abundant in a reef tank. When irradiated with wavelengths shorter than 370-380nm, this phosphorescence can be quite significant.
这个图包含了不同尺寸颗粒的磷光曲线。我们最感兴趣的是60um左右的颗粒，这些在珊瑚缸内大量存在。当被短于370-380纳米波长的光照射时，磷光会非常严重。

Wide spectral diagrams of previous generation LEDs contained a significant portion of 370nm radiation which caused noticeable phosphorescence of suspended particles in the aquarium, hence many DIY LED fixture builders recommended the use very few pure actinic LEDs.
以前的宽频谱的LED包含大量370纳米的辐射，他们会使水中的悬浮颗粒产生显著的磷光。因此，很多DIY LED灯具的爱好者建议尽少使用“光化”LED。
Fortunately, the newest generation of LEDs has an efficient bandwidth of about 30nm [15], and by using LEDs in the 400-430nm range we can avoid the phosphorescence of suspended particles, even though total radiation power can be quite high.
幸好，最新一代的LED的有效波长只有30纳米[15]。使用400-430纳米波段的LED，即使辐射功率很大，我们也一样可以避免悬浮物的磷光。

mynameismo

八、LED灯光谱配置（2）
We shall now try to estimate the amounts of light at selected wavelength ranges: 400-440nm, 440-480nm, 480-520nm, and 520-700nm. Each range will correspond to one color channel in a LED fixture and can be achieved by using one type or a combination of several types of LEDs.
现在，我们来估算一下特定波长范围的光照量：400-440纳米，440-480纳米，480-520纳米，520-700纳米。每个范围对应了LED灯具的一个色彩通道，该通道可以使用一种或多种LED组合而成。
Insolation at the ocean surface depends on the presence of clouds, position of the sun, and other factors. For our estimates we shall assume an average monthly insolation of 1789 J/cm2, based on 3 months statistics for Fiji [20]. Assuming a 12 hours photoperiod, this translates to 413 W/m2.
海洋表面的日照手云层，太阳位置和其他因素的影响。为便于估算，我们根据斐济3个月的统计数据[20]，假定月均日照为1789 J/cm2。假设每天日照12小时，换算得到413 W/m2。

By integration of solar radiation power in accordance with Fig.3, we shall obtain the distribution of visible light power in the above sub-ranges for different depths (Table 2):
根据图3，对特定波段范围的太阳辐射功率进行积分，我们可以得到不同深度下上述各个波段范围的可见光功率分布 (表2):

Table 2 Average light power (in W per sq.m.) for the defined spectral ranges during the day
表 2 一天里，特定波段范围的光能(单位W/m2)

Although the table is based on naturally available spectral distribution at specified depths, note that the 400-500nm range is the most required, since it provides the best coloration and fluorescence in corals; whereas, the longer wavelength radiation in 500-700nm range is poorly utilized by marine photosynthetic organisms. At the same time, the human eye is very sensitive to the 520-600nm range and therefore we do not need very much radiation power in that range: even small amounts of illumination will be sufficient for the eye to perceive the tank as brightly lit. Meanwhile, supplementation of 660nm LEDs can be beneficial for shallow-water organisms. At the same time, this wavelength, in combination with the 400-420nm range, will promote correct rendition of the purple color.
虽然上表数据是根据自然界给定深度下实际光谱分布得到的，但400-500纳米范围的光仍然是最需要的，因为它对珊瑚的显色和发出荧光最有用，而海洋光合生物对于500-700纳米范围长波的利用十分低效。同时，人眼对520-600纳米范围的光波十分敏感，因此对于这个范围，我们不需要很多的辐射能量：即使少量该波段的辐射，人眼就会觉得珊瑚缸被照得很亮了。此外，补充660纳米的LED对于浅水生物是有益的，并且这个波段与400-420纳米波段一起，有利于紫色的正确显色。
As we have shown, the 400-480nm range is most important for marine photosynthetic organisms. In their natural environment corals are getting 52 to 55W/m2 of optical power in the 400-440nm range and 60 to 64W/m2 in the 440-480nm range.
If only these wavelengths are used in the fixture, using the empirical expression Watts/m2 = 0.21*L [19], we can achieve illumination levels between 528 and 567 μmol·photons/m2/s. As it was shown above, this is sufficient for proper growth and coloration of light-demanding corals.
However, we do not recommend using that much radiation power all the time over the reef tank, and the following factors should be considered:
我们之前已经表明，400-480纳米波段对于海洋光合生物是至关重要的。在它们的自然环境中，珊瑚在400-440纳米范围获得52-55W/m2 光照，在440-480纳米范围，获得60-64W/m2 光照。
如果灯具里只用了这些波长，使用经验公式W/m2 = 0.21*L [19]，我们可以得到的照明水平在528到567 μmol·photons/m2/s之间。如前所述，这个水平足以让光合珊瑚很好生长。
然而，我们并不建议一直使用那么大的照射功率，此外还有下列因素需要考虑：

•        Apart from the mentioned wavelength ranges, for an improved visual effect most hobbyists will also utilize LEDs in other ranges. These LEDs will also contribute to total radiated optical power.
•        Radiation power over 400μmol·photons/m2/s can be too high. Production of chromoproteins stops below 100 μmol·photons/m2/s; i.e., at an illumination level 4 times smaller.
•        Many aquarists are using controllers to imitate sunrises/sunsets and other effects, and radiated power may change significantly during the day. Mean power during the photoperiod is less than the maximum power.
•        Marine photosynthetic organisms most efficiently utilize radiation with the wavelengths around 430nm, and this range also stimulates their most intensive coloration.
•        除了上述波长范围，大多数爱好者为了提升视觉效果使用了其他波长范围的LED。这些LED一样增加了总的辐射光能。
•        超过400μmol·photons/m2/s的光照会过强。而低于100 μmol·photons/m2/s以下色素蛋白会停止形成。
•        很多爱好者使用调光控制器来模拟一天里的日出日落效果，不同时刻的光照强度会有很大变化。这种情况下，光照的平均功率会小于最大峰值的功率。
•        海洋光合生物对430纳米的光波利用率最高，这个波段范围使珊瑚发色的能力也最强。

We believe that the most reasonable maximum radiation power should be about 45W/m2 for the 400-440nm range and about 40W/m2 for the 440-480nm range. Note: Here and above we mention optical radiation power rather than the electrical power consumed by the LEDs. To determine the number of LEDs required in a fixture and their rated current these figures must be converted into electrical power, which depends on the efficiency of the LEDs actually used. These calculations, selection of particular LEDs and other matters concerning the actual construction of a LED fixture will be considered in our next article.
我们认为，400-440纳米范围波段合理的最大辐射强度大约是45W/m2 ，而440-480纳米范围是40W/m2。请注意：这里和前面所提到的都是辐射光能，而不是LED消耗的电能。要确定灯具需要的LED数量以及驱动电流，这些数值就需要转化成电能。这个就取决于所采用的LED的能效。在我们的下一篇文章中，会讨论如何计算这些数值，如何选择LED以及与制作灯具相关的其他问题。

If the reef tank is only illuminated in these wavelength ranges for 12 hours, with short sunrises and sunsets specific to the equatorial zone, we will obtain an average radiation power of 400μmol·photons/m2/s, which is sufficient for optimal production of chromoproteins. Since the light fixture is likely to also include LEDs in other wavelength ranges, we can safely assume that these figures include some power margin.
如果珊瑚缸仅使用这些波长的光源照明12小时，并且像赤道地区一样日出日落的时间都较短，我们就会得到一个约400μmol·photons/m2/s的辐射功率，这个光照足够促使生成色素蛋白。由于灯具很可能还包含其他波长范围的LED，我们可以确信这个数值还有一定的余量。

Also note that although 400μmol·photons/m2/s radiation power is optimal for coloration of corals, such high illumination requires pristine water conditions in the tank. Radiation power 4 times below this level is already sufficient to start production of chromoproteins in corals. We recommend starting slowly, with initial lighting levels close to the lower boundary of about 100μmol·photons/m2/s. Within several months you can gradually increase the illumination, while closely monitoring water parameters and the corals' reaction. If the system is stable and all parameters are in the optimal range, optical power can be gradually increased up to 400μmol·photons/m2/s.
值得一提的是，虽然400μmol·photons/m2/s的光照强度对珊蝴色素蛋白形成是有得的，需要非常清澈的水质才能达到这个照明程度。而这个照度的1/4就足以使珊蝴开始生成色素蛋白。我们建议一开始，先从最低限度--100μmol·photons/m2/s开始。几个月内，你可以慢慢地增加照度，但需要密切注意水质情况以及珊蝴的反应。如果系统稳定，各项参数都在最佳范围，那么光强可以慢慢地增加到400μmol·photons/m2/s。

As we have seen, formal parameters such as CRI and CCT are not very useful for determining whether a particular light fixture is suitable for a reef tank. At the same time we need to point out again that sufficient power in the 400-480nm wavelength range is critically important. If this condition is fulfilled, other parameters of the light fixture may be selected based on the owner's individual preferences (just make sure that the total radiated power does not exceed the recommended values). We have to admit, unfortunately, that most of the commercially available light fixtures today are only utilizing the 450nm range and above, whereas an ultimately important range between 400 and 440nm is usually left out, or is inadequately represented.
如我们所见，那些比如CRI和CCT的标准参数对于确定一个灯具是否适合珊蝴缸而言并没有太多用处。同时，我们需要再次指出，在400-480纳米波段范围充足的照明是至关重要的。如果这些条件满足了，灯具的其他参数可以根据个人的喜好来选择（只要确定总辐射强度不要超过前述的建议值）。很不幸，我们得承认，市面上大多数成品灯具仅仅采用了450纳米以上的波段，而极其重要的400-440纳米范围常常缺失或者不足。

mynameismo

References
1.        http://en.wikipedia.org/wiki/Color_vision
2.        David H.Hubel, Eye, Brain and Vision. 256p., 1995, ISBN/ASIN: 0716760096
3.        http://www.ecse.rpi.edu/~schubert/Light-Emitting-Diodes-dot-org/Sample-Chapter.pdf
4.        http://ies.jrc.ec.europa.eu/uploads/fileadmin/Documentation/Reports/Global_Vegetation_Monitoring/EUR_2006-2007/EUR_22217_EN.pdf
5.        http://rybafish.umclidet.com/zooksantella-%E2%80%93-nevolnica-korallov.htm
6.        http://afonin-59-bio.narod.ru/4_evolution/4_evolution_self/es_13_algy.htm
7.        http://medbiol.ru/medbiol/botanica/000a984c.htm
8.        http://batrachos.com/node/442
9.        http://reefcentral.com/forums/showpost.php?p=20296037&postcount=27
10.        http://www.photo-mark.com/notes/2010/nov/19/plancks-despair/
11.        http://reefbuilders.com/2010/06/17/grassy-glow-25000-k-metal-halide-bulb-from-volx-japan-hits-the-mark-for-blue-light-addicts/
12.        http://ies.jrc.ec.europa.eu/uploads/fileadmin/Documentation/Reports/Global_Vegetation_Monitoring/EUR_2006-2007/EUR_22217_EN.pdf - 26p.
13.        R.W.Burnham, R.M.Hanes, C.J.Bartleson Color: A Guide to Basic Facts and Concepts. New York: John Wiley, 1953
14.        Thai K. Van, William T Haller, and George Bowes Comparison of the Photosyntetic Characteristics of Three Submersed Aquatic Plants. www.plantphysiol.org/content/58/6/761.abstract
15.        http://www.led-professional.com/products/leds_led_modules/semileds-achieves-40-external-quantum-efficiency-for-ultraviolet-uv-led-chips
16.        C.D'Angelo, J.Wiedenmann, Blue light and its importance for the colors of stony corals, Coral Magazine, Nov./Dec. 2011
17.        How much electricity costs, and how they charge you
18.        Ecotech Marine's Radion XR30w wins the 2011 Reef Builders LED showdown
19.        http://www.onsetcomp.com/support/knowledgebase/unit-conversion
20.        http://earthobservatory.nasa.gov/Features/EnergyBalance/page2.php
21.        http://reefkeeping.com/issues/2002-09/atj/feature/index.php
22.        Leletkin V.A., Popova L.I., Light absorption by carotenoid peridinin in zooxanthellae cell and setting down of hermatypic coral to depth, Zh. Obshch. Biol. 2005 May-Jun;66 (3)