Mike Shahpurwala 2014-02-26 05:19:02
Proper lighting is as important as magnification for microscopy and video inspection. Image quality can be enhanced by improving illumination, rather than investing in a higher-resolution camera or more advanced software. This guide describes illumination types and products for various applications. Directional Point source lighting, such as from LEDs or fiber optic light guides, is concentrated, intense and flexible. It’s recommended for inspecting and measuring flat objects or those with a matte finish. Glare and shadows limit its suitability for examining other surfaces. Shadowing and glare can occur, though ring lights reduce shadowing when mounted behind a lens – called coaxial illumination. Our 72-LED microscope ring light has brightness and sector controls. Aven also supplies fiber optic ring lights, a Dual Pipe Light Guide and two fiber optic illuminator models. GlancinG This point source alternative aims light at a sharp angle to highlight an object’s surface details and structure – and ideal way to check opaque items and spot defects in parts with depth. Drawbacks of angled illumination are hot spots (“blooming”) and shadows on areas behind the angle of incidence, requiring rotation for a different view. Diffuse This type of illumination, such as from fluorescent ring lights, casts light broadly -- cutting glare and assuring even brightness. Diffuse illumination and diffuse axial illumination (using a beam splitter to reflect light) are best for imaging of large shiny items from. Ultraviolet UV light excites fluorescence in adhesives, laminates, conformal coatings and other materials. Some materials fluoresce differently under short-wave UV light versus long-wave (near-infrared), so purpose-specific illumination should be used. Specialty accessories • Darkfield: A fiber optic darkfield attachment or line light guide directs light so it enters a mineral, glass or plastic specimen through edges perpendicular to the lens. Internal and surface details gain sharp contrast, making flaws more visible. • Backlight: Our fiber optic backlight produces a highcontrast silhouette to increase edge contrast and measurement accuracy if inspection of surface details isn’t needed. • polarizer: A polarizing filter or adapter reduces glare and brings out surface defects for accurate measurement and inspection of shiny surfaces. Aven has a contrast-enhancing polarizer that threads onto a fiber optic ring light model. Illumination has a direct impact on costs, accuracy and productivity. As with larger production workplace investments it’s helpful to consult a supplier specializing in optical instruments and professional tools, as Aven has done since 1983. aven p: 734-973-0099 f: 734-973-0097 e: firstname.lastname@example.org www.aventools.com
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