1. Chromatic aberration
When white light passes through an ordinary lens, axial chromatic aberration allows blue light and red light to be focused in different positions on the optical axis, resulting in a clear focusing of a certain colour while other colours are fuzzy; chromatic aberration of magnification makes the edges of the image appear as red and blue coloured stripes, as if the object is set with a rainbow edge. This phenomenon is essentially the glass of short wavelength light (blue light) refractive index is higher than the physical properties of long wavelength light (red light) caused by the high power microscopic observation will seriously interfere with the identification of details.
2. An achromatic design
Standard microscope objectives incorporate an achromatic design whereby the chromatic aberration is cancelled out by two sets of glass lenses with opposing properties: coronet glass with weak dispersion but good light transmission, and flint glass with strong dispersion but high refractive index. By gluing a convex Coronet lens to a concave flint lens, the tendency of the convex lens to shift the focus of the blue light forward is cancelled out by the reverse action of the concave lens, which ultimately brings the red and blue light together in the focal plane of the standard microscope objectives. This design is like making two materials with very different temperaments work together - the convex lens pushes back the focus of blue light, and the concave lens pulls forward the focus of red light, achieving optical balance through precise calculations of curvature and material, and correcting the spherical aberration of yellow-green light at the same time.
3.Applicable from laboratory to industry
In biological experiments, the red and blue fuzzy bands at the edge of cells are eliminated, so that the chromatin structure of cell nuclei is easier to distinguish; in industrial inspection, the coloured halo of the metal microstructure disappears, and the measurement error of crack size can be reduced by more than 40%. Compared with the compound achromatic objective, standard microscope objectives cost about 60% less, but can meet 90% of the clarity needs of routine observation - for example, students with a 40 times the objective lens, the onion epidermal cells of the cell wall texture can be clearly discerned without having to bear the high cost of top-quality objective lens. without the high cost of a top-of-the-line objective lens.
