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Basler Lens C23-3520-2M-S#

Basler Standard C-mount lens with a fixed focal length of 35 mm, aperture range from F2.0–F16, and a resolution of 2 MP.

Basler Lens C23-3520-2M-S F2.0 f35 mm

Key Features#

  • Fits all Basler cameras with a sensor size of up to 2/3"
  • Metal housing
  • C-mount
  • Locking screws for iris and focus


The technical data shown in the following sections are nominal design values. The real values of the delivered products can deviate from the nominal design values.

General Specifications#

Order Number 2200000182
Focal Length f' 34.3 mm ± 5 %
Aperture Range F2.0–F16
Image Circle 11 mm (2/3" format)
Focus Range 0.35 m to infinity
Optimum Working Distance 1.0 m
Optimum Magnification -0.035
Relative Illumination at Full Aperture At least 84 % (see Relative Illumination versus Image Height)
Resolution (25 % MTF, Center, Full Aperture) Designed for 90 LP/mm (5.5 µm pixel size, see Resolution versus Image Height)
Optical Distortion Typical -0.5 % (barrel distortion, see Distortion versus Image Height)
Angle of View, 1/1.8" Format (using an IMX265 sensor) Horizontal: 10.6° (@ MOD) to 11.7°
Vertical: 8.0° (@ MOD) to 8.8°
Angle of View, 2/3" Format (using a PYTHON 2000 sensor) Horizontal: 13.6° (@ MOD) to 15.1°
Vertical: 8.6° (@ MOD) to 9.5°
Wavelength Range Visible (400–700 nm)
Pupil Magnification, ß'P 1.03
Chief Ray Angle, CRA 8.61°
Front Focal Length, sF -11.1 mm
Back Focal Length, s'F 10.1 mm
Principal Point Separation, HH' -14.4 mm
Entrance Pupil Position, sEP 22.2 mm
Exit Pupil Position, s'AP -24.7 mm
Overall Optical Length, d 32.5 mm

→ See Terminology (Basler Lenses).

Mechanical Specifications#

Flange Back 17.526 mm
Mount C-mount
Weight Approx. 81 g
Focus/Iris Operation Manual
Operating angle: 262°

Lens Dimensions#

Basler Lens C23-3520-2M-S

→ Download the CAD/technical drawing for your Basler Lens.

Precautions, Mounting, and Cleaning (Basler Lenses)#

→ See Precautions, Mounting, and Cleaning (Basler Lenses).

Environmental Requirements#

Temperature During Operation -10–60 °C (14–140 °F)
(For best results, adjust the focus when a steady operating temperature has been reached.)
Humidity During Operation 20–80 % relative humidity, non-condensing
Temperature During Storage -20–70 °C (-4–158 °F)
Humidity During Storage 20–70 % relative humidity, non-condensing

Performance Charts#

Relative Illumination versus Image Height#

Relative Illumination versus Image Height

Distortion versus Image Height#

Distortion versus Image Height

Resolution versus Image Height#

Conditions: f/2.0, polychromatic, 0.5 m working distance, average result based on 10 samples

Resolution versus Image Height