The LED handle has the advantage that the LED lamps should not need to be replaced (whereas bulbs burn out and need periodic replacement), and the battery life is extended. Rechargeable batteries can be used in either handle. The incandescent battery handle requires two C batteries which last much longer. It requires three C size batteries which last approximately three hours. There is actually another option - a halogen battery handle, but it is suggested that it be purchased as a companion to the plug-in handle for use only in special situations. This need for power is the reason that the halogen handle sports a 110-120V power cord. The electrical assemblies of the handles are specific to the type of bulb.Ī halogen bulb is whiter, brighter, and draws more power than an incandescent bulb. The bulb types are NOT interchangeable on the handles. Three types of handle are available: an incandescent battery handle, and a halogen handle, and an LED handle. The handle is designed so that when it is connected to the head the entire unit will lie flat on a table to form its own stand. The second part of the magnifier is the handle. The images be low were taken with increasingly stronger magnifiers - 4X, 7X and 10X. If you have several heads and just one handle, and the net result is that you have several magnifiers. No matter what handle you decide on, any head will match. For those situations where a closer image is needed, the 7X head is my choice. With either a 35 mm camera plus extension ring or a digital camera plus zoom, the 4X yields good detailed photos. The 4X head has a comfortable working distance and a useful field size. But the price of using an aspheric lens is that the eye must be at a specific working distance from the lens to avoid the distortion.Īfter a thorough examination of the various lenses available, the ones I find most useful are 4X and 7X. Eschenbach minimizes this distortion by using a lens with aspheric curvature. Also, as powers of magnification increase, there is some distortion as you look away from the center of the lens. There are heads available at several magnifications (3X, 4X, 5X, 6X, 7.5X, 10X, 12.5X).Īccording to the laws of optics, as magnification increases, the field of view decreases. I prefer the round head because camera lenses are round. The head is a circular or rectangular unit which consists of a housing and the magnifying lens. Illuminated stand magnifiers have two parts - the head and the handle. A stand magnifier is excellent for any type of work because the magnifier body is its own stand. ![]() There are several types of magnifiers available. The illuminated magnifier I use so much is actually part of a system of illuminated magnification products by Eschenbach. And, speaking of invisible, EDD (electrostatic detection device) equipment reveals and demonstrates "indented writing." The most useful areas of the spectrum for the document examiner are the Ultraviolet and Infrared wavelengths, which allow the differentiation of similar appearing inks and the review of normally invisible security features. A variety of specialized light sources extend the examiner's eyes into portions of the electro-magnetic spectrum where they can not go unaided. Combining those devices with cameras allows the examiner to study and compare images and to present illustrations to clients and fact-finders. Magnifiers and Microscopes make small details visible and measurable. Technology and instrumentation are a great aid to the document examiner. Forensic Document Examination is a field with many subsets, as explained on the Applications page. The most important tool a document examiner has is his or her own vision, but in this section and the laboratory tour section we will consider the external tools which enable the examiner to see, evaluate and record more than is apparent to the unaided eye.
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