Focus Measuring Magnifier 'Achromat'

A high precision lens with fine scale at the bottom- the lens provides a sharp image with a high resolution,  excellent strength and clarity.

This magnifier is an "achromat" which provides color corrected images so you can view the true color of the examined object.

• focusable measuring magnifier
• 10x magnification
• 21 mm lens diameter
• light weight aspheric lens
• precision scale: 30 mm length with a 0.05 mm division
  

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.

As can be seen above, 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.