The 20x measuring magnifiers are wide-angle magnifiers with 15x, 20x or 30x magnification in combination with a glass scale with 0.1 mm or 0.5 incrementations (see spec for details). This magnifier has been redesigned for focussed observation of the entire 20mm, 12mm or 7mm diameter field. The field curvature as well as the lateral chromatic deviation have been corrected perfectly by a combination of four lenses. Two of the lenses are produced using a new type of optical glass. Moreover all six air/glass interfaces have a multiple coatings to prevent internal reflections (anti-reflex coating) Two additional black scales and two white scales are available for these measuring magnifiers (see overview) A very large field of view and measuring range in relation to the magnification factor have again been achieved with this perfect optical system.

Summary

magnification 15x, 20x, 30x

• focusable
• field of view: Ø20mm, Ø12mm, Ø7mm
• scale length (see specifications)
• Triplet glass lens (distortion free)
• achromatic
• dimensions (see specifications)
• weight 35 grams
• case included
• standard scale included

The Triplet lens-system combines the aplanatic features of a distortion-free image with the color correction of an achromatic lens making this magnifier a highly important tool for viewing the true color of the examined object.

Specifications:

Chromatic aberration is caused by a lens having a different refractive index for different wavelengths of light (lens dispersion), meaning that different colors focus at different distances from the lens. Longitudinal and lateral chromatic aberration of a lens can be seen as "fringes" of color around the image.

Chromatic aberration of a single lens causes different wavelengths of light to have differing focal lengths.

An achromatic doublet has the same focal length for red and blue light.

Chromatic aberration can be minimized by using an Achromatic Lens or Achromat, in which special optical materials with differing dispersion are assembled together to form a compound lens.