Halo lit (or reverse) channel letters can produce a dynamic signage presence when properly designed and installed. However, the color, brightness and halo depth can have a substantial impact on the effectiveness of this type of letter sign. This article examines some of the elements and characteristics for effective reverse lit channel letter halos.
光暈照明（或背光式）槽形字經過適當地設計和安裝之后，可以呈現出動態的顯現方式。同時，顏色、亮度和光暈深度對這種類型的標識呈現效果都有很大的影響。這篇文章研究了幾種高效的背光式槽型發光字光暈的屬性和特征。

Halo Color
光暈顏色

Many clients are not aware that reverse channel letter halos are available in multiple colors. (Some assume white is the only option.) Choosing the correct halo color configuration can be an important effectiveness determinant. This multiple color capability may also permit a client to match a customers branding color scheme.
許多客戶還沒有意識到，背光式槽型發光字光暈可以使用多種顏色。（一些人以為白色是唯一的選擇。）選擇合適的光暈顏色對標識呈現出的效果有很大的影響。這種多重色彩顯現方式或許還能滿足客戶對品牌顏色設計的要求。

Consider the halo color on Photo 1 below.
以下面的圖1為例，觀察一下光暈的顏色。

The warmth of this orange halo is an appropriate complement to the product offering. The color orange is often associated with physical comfort and food.
橘色光暈呈現出的溫暖感正好符合此標識想要表達的立意。橘色通常都是與身體舒適度和食物相關聯的。

Mixing the signs halo colors is another design item to consider. Your client may also not be aware that not all letters must have the same halo color. Multiple halo colors can provide the sign with an additional attention generating element.
采用混合光暈顏色是另外一個設計理念。客戶可能意識不到，不是所有的發光字都只能使用同一種顏色的光暈。多重光暈顏色可以為標識增添額外的吸引力。

For example, Photo 2 features multiple halo colors and has both strong legibility and visual impact.
例如，圖2中標識的特點就是多重顏色的光暈，顯示出較強的易讀性和視覺沖擊。

Photo 3 also mixes halo colors and has a warm and professional appearance. Red is one of the Residence Inn branding colors.
圖3中的標識也混合了光暈顏色，呈現出一種既溫暖又不失專業化的外觀。其中紅色是Residence Inn品牌顏色之一。

Photo 4 is another example of a halo color mix. This illumination design emphasizes the business name but then follows with the business type in a smaller font and different halo color.
圖4是另外一個混合光暈顏色的案例。這個照明設計重點在于企業名稱，后面緊接著是企業類型，它用的是較小的不同顏色的光暈。

Multiple halo colors may be an excellent method for your client to add more attention generating capacity to their reverse lit letter sign.
多重光暈顏色對客戶來說或許會是最佳選擇，這樣他們的背光式發光字標識就會吸引更多的目光。

However, that is not always the case. A single halo color (white is the most common) may also be a perfectly appropriate configuration. Consider Photo 5.
然而，多重光暈顏色并不是所有的標識都適用。單一光暈顏色（白色是最普遍的）或許也是一種絕佳的外觀選擇。觀察一下圖5.

This sign has an excellent outline against the well proportioned white halo. The single color seems appropriate for the business type as white is often associated with cleanliness and purity. Importantly, the building also has a white façade which adds to the halo luminance.
這個標識有一個比例適當的白色光暈輪廓。單一顏色很適合該企業類型，因為白色通常是和純潔相關聯的。更重要的是，店面的正面是白色的，它和白色光暈更加匹配。

Halo Brightness
光暈亮度

Adequate halo brightness is a critical factor in the effectiveness of a reverse channel letter set. Some letter sets lack sufficient light intensity to generate an optimal halo lit effect.
適當的光暈亮度也是背光式槽形發光字呈現效果的決定性因素。一些發光字的亮度不夠，所以很難呈現出最佳光暈效果。

Part of the site survey must include the environment in which the sign will function. Letters which are mounted indoors have a stronger halo brightness requirement. For example, in Photo 6, this indoor mounted reverse letter set has some width distribution but lacks adequate brightness:
一些場所必須考慮標識呈現效果所需要的環境。室內發光字需要更強的光暈亮度。例如，在圖6中，該室內背光式發光字有一定寬度但是亮度不夠：

This halo is not sufficiently conspicuous to create an “illumination bed” that fully outlines the sign letters. This effect may be the result of an inadequate number of LED modules, modules which have dimmed over time or failure to use a reflective paint on the letter interiors.
此光暈呈現出的照明效果不是特別明顯，不能完全顯示出標識字母的輪廓。這可能是由于LED模組不夠造成的，模組會隨著時間推移變暗或在發光字底部無法反射顏色。

Conversely, note the impact difference between that sign and this well illuminated set (also mounted indoors) in Photo 7.
相反地，我們來看一下這個標識和圖7 中良好照明標識（同樣是室內標識）的區別。

The letter interior configuration can be a partial determinant of halo brightness. Channel letter cans are typically constructed of aluminum, and reverse letters have both aluminum returns and faces (as opposed to the acrylic faces used on front lit letters.)
發光字內部結構是光暈亮度的決定性因素。槽形發光字字殼是用鋁做成的，并且背光式發光字正面和背面都是用鋁做成的（亞克力用于正面發光字。）

The default mill finish of an aluminum letter interior does not effectively reflect LED illumination. Reflective white paint is available to distribute and amplify the illumination reflection from the inside of the letter can. Painting the letter interiors for added illumination “bounce back” is a strong step toward a bright and well distributed halo.
表面經過打磨的鋁字，其內部反射LED照明的效果不是特別明顯。反光白漆可均勻地散布并增大發光字字殼內部的照明反射范圍。為了有額外的照明“反射”效果，在發光字內部噴漆是實現明亮均勻散布光暈的重要步驟。

Last, one further step down from inadequate brightness is a halo which is conspicuously dim. Assuming these dim letters are LED (not neon) illuminated, this problem may be caused either by an inadequate LED module population or by LED which has dimmed over time and needs replacement.
最后，造成標識亮度不夠的另一個原因是光暈明顯變暗。假設這些暗淡的發光字都是用LED（不是霓虹燈）照明，那么導致標識暗淡的原因要么是LED模組數量不夠，要么是LED已經隨時間推移變暗，需要更換新的LED來照明了。

A dim halo can be worse than no halo at all. It is essentially an advertisement for a sign that was either poorly constructed or has been not been properly maintained. Either way, it is not positive advertising.
暗淡的光暈比沒有光暈更糟糕。標識實質上就是廣告宣傳，如果光暈比較暗淡，原因要么是制作的很差，要么是沒有進行適當地維護。無論哪一種原因，它都不是一個積極的廣告宣傳。

Halo Width
光暈寬度

Halos also vary in terms of width (i.e., the distance behind the letter that the halo “fans out.”) Ideally, the halo will form an “illumination bed” against which the letters will be outlined. A halo which combines both brightness and appropriate width can create a dramatic illumination effect.
光暈寬度（即光暈在發光字后面散開的距離）也分為很多種。理想情況下，光暈會在發光字輪廓下形成照明帶。亮度和寬度均適當的光暈能夠給人留下深刻的印象。

On the other hand, an overly thin halo may defeat the reverse lighting purpose. If the halo does not disperse an adequate distance behind the letters, the illumination impact can be diminished. (See Photo 8)
同時，太過纖細的光暈可能會使背光式照明效果大打折扣。如果光暈在發光字后面散開的距離不夠時，照明效果就會減弱。（見圖8）

One of the causes of halo width is the letter mounting distance from the wall.The appropriate mounting distance is typically 1.5” to 2”. Letters which do not have sufficient façade mounting distance may result in a thin halo.
發光字與墻面之間的安裝距離是影響光暈寬度的因素之一。最佳安裝距離通常是在1.5”到2”之間。如果安裝距離不夠就會造成光暈太過纖細的后果。

Facade Color Effect
發光字正面顏色

A careful examination must also be made between the customers desired halo color and the current color of the building façade. Halo illumination may appear in a different hue than intended if it is reflected off a colored building surface.
要仔細觀察客戶要求的標識光暈顏色和現有建筑物表面顏色之間的匹配度。如果反射正面為彩色的建筑物，光暈照明可能會呈現出和預期不一樣的色調。

For example, if a building has a red façade and the installed sign has a white halo, some of the red surface color may carry over into the halo appearance. The customer should be made aware of that potential issue prior to installation.
例如，如果建筑物的正面是紅色的，而標識的光暈是白色的，那么部分紅色就會融進白色光暈中。客戶在安裝之前首先要考慮到潛在的問題。

If your review of the site shows there may be a potential surface color carry-over problem, one potential solution is to mount a backer panel behind the sign. The correct usage of such a panel can change a problematic illumination surface to an ideal halo lighting environment, as seen in Photo 9.
如果你覺得這個位置可能會出現正面顏色融合的問題，那么解決方案就是在標識后面安裝一個支撐面板。正確使用這種面板可以解決顏色融合問題，從而變成理想中的光暈照明效果，如同圖9中的標識。

However, reverse letters mounted to backer panels may also have issues. For example, if the panel has a shiny surface (like a “mirror finish”) it may show a night reflection of the LED modules.
然而，安裝在支撐面板上的背光式發光字同樣也存在一些問題。例如，如果這個面板的表面有光澤（如同“鏡面”），可能會出現LED模組的夜間反射現象。

The key question for your customer is their color preference on the overall halo appearance. If you see a potential issue at the sign location (i.e., the surface color may dilute the halo color) let them know the importance of a backer panel.
客戶在意的是整個光暈呈現出的色調。如果你覺得會出現發光字表面顏色削弱光暈顏色的現象，那么就告知客戶支撐面板的重要性。

Conclusion
結論
Halo lit channel letters can have a dramatic signage impact when constructed correctly, but vary in terms of halo and mounting quality. The halo color, brightness and width can each have an impact on the overall presentation of the reverse lit sign. Further, the mounting surface and color will also influence the halo appearance. A careful site survey will help to uncover potential issues with the reverse lit letter set appearance.
制作良好的光暈照明槽形發光字會有出人意料的效果，同時光暈和安裝質量都略有不同。光暈顏色、亮度和寬度都會對整個背光式照明標識有一定影響。更進一步講，安裝面板和它的顏色也會影響光暈的呈現效果。細致的研究調查會讓你發現背光式發光字外觀存在的潛在問題。
*文章來源于亞洲標識