Theia SY125A lens image
Theia SY125A lens drawing
Theia SY125A lens mounted on SeeSense camera
Theia SY125M lens mounted on Pacific Corporation camera

Theia SY125A 125° CS-mount 1/2.5" F1.8-C 5MP DC Iris rectilinear prime lens

Regular price £390.00 £390.00 Sale

The Theia Technologies SY125A 5 Megapixel 1.28mm CS-mount lens achieves 125° horizontal angle of view on a 1/3” sensor using patented Linear Optical Technology®.  It achieves an ultra-wide field of view with ULTRA LOW DISTORTION (<3% barrel).  It is suitable for camera sensors up to 1/2.5" and has a DC- Auto Iris from F1.8-Closed.

The superior quality of this lens combines stunning performance with the highest build quality and will support sensor technology up to 5 megapixels resolution. It is ideal for a wide range of security, broadcast and industrial vision applications. This lens is also available in Manual iris CS-mount SY125M and C-mount MY125M. 



  • 1.28 mm lens
  • FULL HD 5MP Resolution
  • Ultra Low Distortion
  • Integrates with 1/3” 1-CCD / CMOS HD cameras
  • Robust, precise mechanics
  • Weight 118 grammes
  • Uses Linear Optical Technology®
    N.B. The lens image will be inverted so the camera should be mounted upside down or the image inverted electronically
Focal Length 1.28mm
Image Format 1/3" up to 1/2.5" (with slight vignetting)
Adjustment Manual focus with locking screws, DC iris
Aperture Range F1.8 - Closed
Angle of View (H x V) 125 degrees x 109 degrees (H x V) (1/3" Sensor)
Image Circle 6.0mm diameter
Pan Focus Distance 0.5m - infinity
Modular Transfer Function 200 lp/mm centre, 140 lp/mm @>20% edge
Minimum Object Distance 0.5m (0.1m by adjusting back focus)
Resolution Up to 5MP
Distortion <3% barrel at image edge (for 1/3" sensor)
Back Focus Adjustable
Flange Focal Length 12.5mm (in air)
Mount CS-mount (metal)
Weight (g) 118 grammes
Dimensions 33mm (diameter) x 59mm (length)
Operating Temperature -20 to +50 degrees C


PRODUCT DATASHEET:                                     

Theia SY125A Lens Data Sheet (PDF)