Process of using zoom stereo microscope ADJUSTMENTS If necessary regulate: The set screws of the prisms housing The tension of the cables of the focusing system The brake on the carriage The position of the intermediate plate along the column The interpupillary distance of the binoculars Focus the binoculars to the infinity Place in the binoculars in their seats and place them in center Open the diaphragm of the zoom at the utmost When you adjust the interpupillary distance, the images can split. Shift the arrangement of the binoculars a little in anticipation of they overlap again. In fact, moving the binoculars causes a minor change in the position of the slides, For this reason the prisms.

Adjustment of the parfocality. The parfocality is a condition in which, when you show a discrepancy, the magnification, the image remains in focus. If this does not happen, try to transform the focusing of the binoculars or of the zoom objective until you accomplish it. SUPPORTING PLANE At the same time as this zoom stereo microscope to a certain extent tall, if you want to use it when you are sitting, you have to put it on a low surface. ILLUMINATION By means of a quite powerful and directional light, you will have high-quality light and shadow effects which will bring out the relief and the colors of the samples. To this end, you can use a 20_Watt halogen task lamp. There is a model with a magnetic support which allows you to orient the lamp. Unfortunately, this light gives off a lot of infrared radiation. If you want avoid desiccating the insects you are observing, avoid prolonged exposures to strong light and release the specimen soon after the observation. To decrease this problem, filter the light using a heat absorber filter that gives a more cold light. You can find such filters in slide projectors or in a camera shop. By and large illumination by transmitted light requires a less powerful lamp, but one adjustable in intensity. Try bare filament and polished-reflector lamps. In excess of 50 magnifications, you will have to make available a bright and diffuse illumination, or else the resolution of the zoom stereo microscope will be lowered. Out-of-doors you can use the direct light of the Sun. At any rate, as it come from a perceived point source, this light is not suitable for high magnifications because it produces a sort of grainy appearance, which decreases the sharpness of the images. In this case, to perceive the smallest possible details, place a white screen just about the sample to obtain a diffuse illumination. The quality of the image depends for the most part on the quality of the optics you use for the construction of this instrument; however, you will soon notice that the illumination also has an enormous effect.

MAINTENANCE Carry on the zoom stereo microscope in a dry room and if it is possible in its box. Do not leave it exposed to dust, but cover it. Now and then, check that the column is dirt free. If necessary, clean it with a dry cotton cloth. Verify the instrument works fine and adjust the screws if necessary. Try to keep away from the need to clean lenses and prisms. Optical surfaces should hardly ever be cleaned and this operation has to be performed with great care. To this end, use special optical paper, or a clean cotton cloth. Do not use ordinary paper because often it contains minerals used as fillers . which would damage the lenses.