Sign & Digital Graphics

July '16

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30 • July 2016 • S I G N & D I G I T A L G R A P H I C S ELECTRIC SIGNAGE requirement. For example, this indoor mounted reverse letter set has some width distribution but lacks adequate brightness (see photo 6). This halo is not sufficiently con- spicuous to create an "illumination bed" which fully outlines the sign letters. This effect may be the result of an inadequate number of LED modules, modules that have dimmed over time or failure to use a reective paint on the letter interiors. Conversely, note the impact differ- ence between that sign and this well illuminated set, also mounted indoors (see photo 7). The letter interior conguration can be a partial determinant of halo bright- ness. 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.) The default mill nish of an alumi- num letter interior does not effectively reflect L E D illumination. Reflective white paint is available to distribute and amplify the illumination reection 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. Last, one further step down from inadequate brightness is a halo that is conspicuously dim. Assuming these dim letters are LED (not neon) illuminated, the problem may be caused either by an inadequate LED module population or by an LED that has dimmed over time and needs replacement. A dim halo can be worse than no halo at all. It is essentially an advertisement for a sign that was either poorly con- structed or has been not been properly maintained. Either way, it is not positive advertising. Halo Width 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 that combines both brightness and appropri- Photo 6: Reverse lit letters with inadequate halo brightness. Photo 7: Reverse channel letters with a bright yellow halo. Photo 8: Reverse lit sign with thin halo.

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