Iris Mount: C-Mount
Additional Information FA Industrial Type.
Locking Screws (Focus and Iris).
Recommended for cameras up to 1.5 megapixel resolution.
Focal Length (mm) 50
Lens Type Fixed
Image Size (mm) 2/3" (Φ11)
Iris Range (F-stop) F2.0 ~ F22
Focusing Range (m) 0.5 ~ ∞
Iris Control Manual Focus Control Manual Shooting Range at M.O.D. (mm) 85.0(H) x 63.6(V) Angle of View 2/3" (°) 10.1 x 7.6 Angle of View 1/2" (°) 7.3 x 5.5
Angle of View 1/3" (°) 5.5 x 4.1 Horizontal
Angle of View (°) 10.1° Vertical
Angle of View (°) 7.6° Diagonal
Angle of View (°) 12.6° Horizontal Shooting Range at M.O.D. (mm) 85.0 Vertical Shooting Range at M.O.D. (mm) 63.6 Diagonal Shooting Range at M.O.D (mm) 106.6 Resolution (Center, Corner) 100lp/mm, 60lp/mm
TV Distortion (%) -0.1
Back Focus in Air (mm) 17.2
Mount C-mount Filter Thread Size (mm) M30.5 x P0.5
Minimum Focus Distance (m) 0.5
Flange Back in Air (mm) 17.526
Front/Rear Effective DIA (mm) Φ24.6, Φ15.4 Exit Pupil (mm) -42 Size (mm) Φ32 x 39.5
Weight (g) 88
Temperature Range (°C) -10 ~ +45
Further information: History of the telescope
With the invention of the telescope and microscope there was a great deal of experimentation with lens shapes in the 17th and early 18th centuries trying to correct chromatic errors seen in lenses. Opticians tried to construct lenses of varying forms of curvature, wrongly assuming errors arose from defects in the spherical figure of their surfaces. Optical theory on refraction and experimentation was showing no single-element lens could bring all colours to a focus. This led to the invention of the compound achromatic lens by Chester Moore Hall in England in 1733, an invention also claimed by fellow Englishman John Dollond in a 1758 patent.
Related information about the index fiber
In graded-index fiber, the index of refraction in the core decreases continuously between the axis and the cladding. This causes light rays to bend smoothly as they approach the cladding, rather than reflecting abruptly from the core-cladding boundary. The resulting curved paths reduce multi-path dispersion because high angle rays pass more through the lower-index periphery of the core, rather than the high-index center. The index profile is chosen to minimize the difference in axial propagation speeds of the various rays in the fiber. This ideal index profile is very close to a parabolic relationship between the index and the distance from the axis.
Knowledge about the objective
Some microscopes make use of oil-immersion objectives or water-immersion objectives for greater resolution at high magnification. These are used with index-matching material such as immersion oil or water and a matched cover slip between the objective lens and the sample. The refractive index of the index-matching material is higher than air allowing the objective lens to have a larger numerical aperture (greater than 1) so that the light is transmitted from the specimen to the outer face of the objective lens with minimal refraction. Numerical apertures as high as 1.6 can be achieved.The larger numerical aperture allows collection of more light making detailed observation of smaller details possible. An oil immersion lens usually has a magnification of 40 to 100×.