Balluff MATRIX VISION mvBlueGEMINI - Page 39

mvBlueGEMINI Technical Manual (EN) v2.6
APPENDIX 38
The resolution - a little physics
Actually, you have to consider the wavelength of the light, because the light makes the image.
The wavelength of the visible light is between 0.4 µm and 0.6 µm.
The smallest imaged point results from the aperture which will never be smaller than 0.5
µm. Realistic figures are between 2 µm and 5 µm.
B = 1.22 * 2 * λ * F / D
B = Diffraction disk or point image
F = Focal length
D = Aperture diameter
Example with green light and λ = 0.5 µm
F-number F/D
Diameter diffraction disk
1
1.25 µm
4
5 µm
16
20 µm