6.Filters and Lenses
© 2023 China Daheng Group, Inc. Beijing Image Vision Technology Branch 110
3)
Resolution
The resolution represents the ability of the lens to record the details of the object, usually in units of
line pairs that can be resolved per millimeter: line pair/mm (lp/mm). The higher the resolution of the
lens, the sharper the image
When selecting a lens, make sure that the accuracy required by the system is less than the resolution
of the lens
4)
Working distance
The distance from the first working surface of the lens to the object being inspected
When selecting a lens, make sure that the working distance is larger than the lens parameter
"minimum object distance"
5)
Focal length
The focal length is the distance from the center point of the lens to the clear image formed on the focal
plane. The smaller the focal length value, the larger the field of view of the digital camera
For focal length calculation, we need to confirm three parameters: the field of view, the sensor size of
the digital camera and the working distance. The focal length (f) of the expected lens can be calculated
by the following formula
f = sensor size (horizontal or vertical) * Working distance / Field of View (corresponding to the horizontal
or vertical direction of the sensor size)
The corresponding lens is selected by the calculated focal length.
6.2.1.
HN-2M Series
The HN-2M series lenses are 2 megapixels lenses for industrial, suitable for sensors with max. image
circle of 1/2" ~ 2/3". This series of lenses has the following features:
High optical performance with optical design supporting up to 2/3" sensor size, 6.2μm pixel size (up
to 2 megapixels) sensor. 8 models with F values below 2.8, clear images can be obtained even in low
light environment
Excellent anti-shock and anti-vibration performance, with a unique mechanical structure, the optical
axis fluctuates below 10µm
The housing is small and compact, the minimum outer diameter is only
φ
29.5mm, and it can be
installed in various limited spaces
Easy to install, there are 3 fixing holes on the lens barrel for fixing the iris and focusing. The best fixing
hole can be selected according to the installation environment
Models:
HN-0612-2M-C1/2X