How to use the collimating screw in a tool microscope
Adjusting the focus using the collimating screw to find the object is arguably the most important step in the use of the instrumental microscope. Never make the following mistakes in operation: first, adjusting the focus directly at high magnification; second, always looking at the field of view in the eyepiece regardless of whether the barrel is raised or lowered; third, not understanding the critical value of the object distance, and adjusting the object distance up to 2~3 cm while still adjusting upward and turning the collimating spiral very fast. The first two errors often result in the objective lens against the mount, damaging the mount or lens, while the third error is one of the most common when using a microscope.
Adjustment of the focal length must be adjusted at low magnification, first turn the coarse focusing spiral, so that the lens barrel slowly down, the objective lens close to the slide, but do not let the objective lens touch the slide, in the process of the eye to look at the objective lens from the side, and then use the left eye towards the eyepiece to gaze inside, and slowly reverse the adjustment of the coarse focusing spiral, so that the barrel of the lens rises slowly, until when the object is seen to see the object image at the same time, while the general objective distance of the microscope is in the range of about 1cm, so if the Object distance is far more than 1 cm, but still do not see the object image, it may be the specimen is not in the field of view or turn the coarse focusing spiral speed is too fast, at this time should be adjusted to the position of the mount, and then repeat the above steps, when the field of view of fuzzy object image, we must switch to the fine focusing spiral adjustments, only in this way can narrow the scope of the search to improve the speed to find the object image.
