Epi-fluorescent Illumination Alignment Obj Lens
The recommended sequence for focusing and aligning any epi-fluorescent lamp is presented below. Initially, a lamp that is freshly installed and unaligned may have a variety of orientations when the arc is focused by adjusting the collector lens. An example is illustrated in Panel A, where the arc image is positioned in the upper left and the mirror image is displaced to the lower right. After aligning the arc images and adjusting the mirror position and focus, an image similar to that shown in Panel B should appear. Merging the arc image into its mirror image will result in an overlap such as the one illustrated in Panel C. Finally, when the collector lens is defocused to illuminate the entire viewfield (Panel D), an evenly distributed and symmetrical beam should result. If this is not the case, the arc should be re-focused and the alignment procedure started fresh. Visitors are encouraged to practice using the tutorial until they can easily achieve these results.
To begin alignment of the arc lamp, focus the collector lens (see below pic) to produce a sharply defined image of the bulb. Centering knobs built onto the lamp-house exterior can then be used to translate the focused arc image directly into the center of the illumination circle produced. Some lamp houses have an internal mirror system that directs a more intense illumination into the aperture. Microscopes equipped with this type of lamphouse will produce two arc images (the actual arc and its mirror image). Use the mirror centering and lamp translation knobs to position the real arc and its mirror image (which is usually less intense) side-by-side, and then use the mirror focus knob to adjust the intensities until they are approximately equal (lamp-houses lacking the mirror system will also lack the adjustment knobs, so carefully check the manufacturer’s instructions on lamp adjustment). Finally, use the lamp adjustment knobs to overlay the arc and mirror images as closely as possible.
Once you see the light, follow these steps to have the maximum brighness and right at the center: