To the category: Microscope eyepieces
SIGETA WF 16x/13mm - achromatic 16x eyepiece in a metal housing. The eyepiece barrel diameter is 23.2mm, which is standard for most student and professional biological microscopes. The calculated eyepiece number for this model is 208: this value is situated in the central part of the WideField interval (180..225), therefore it is no exaggeration to classify the eyepiece as wide-field.
The schematic structure of the SIGETA WF16x/13mm eyepiece is Kelner type II. The optical part consists of three lenses, two of which are glued on place of the eye lens in order to correct chromatic aberrations and the third (field lens) is biconcave. The convex surfaces curvature is chosen to reduce spherical distortions
The schematic table of eyepiece properties of the WF16x:
|Angular field of view
|Colour rendering at edge of field
|Observation comfort (pupil extension)
|Spherical aberration correction
"+++" is the maximum quality achieved by an eyepiece arrangement of 2 or 3 elements at the same magnification
When used with a laboratory microscope equipped with a large aperture immersion objective, the WF 16x/13mm eyepiece allows 1600x magnification. Alternatively, by adding such an eyepiece to a good teaching microscope, it allows the child to operate at 640x magnification in the customary way - without the use of vegetable oil, with a "dry" objective at 40x.
All in all, in terms of image quality/cost ratio, the SIGETA WF16x/13mm eyepiece is the best choice for occasional observation at high magnification. For constant exploration it is better to prefer Plesla or Erfle multi-coated eyepieces.