America’s Security Experts Since 1989    |   12 reasons to shop with us >


M-F 8am-6pm CT

9,000+ Reviews

Theia SL183A | 5.0 Megapixel Ultra-Wide Angle DC Auto-Iris CS-Mount Lens

Theia 5.0 Megapixel Ultra-Wide Angle Varifocal DC Auto-Iris CS-Mount Lens

115° field of view without barrel distortion
  • 77-115 degree field of view using Linear Optical Technology
  • Use on cameras up to five megapixel resolution
  • IR corrected for use with true day/night cameras
  • Compatible with 3S, LG & HD security cameras
In stock
115° field of view without barrel distortion
Ships same business day when ordered by 3:00 pm Central Time.
  • Free Expedited Shipping for most order over $299
  • Industry Leading Warranties + Expedited Exchanges
  • Hassle-Free 30-Day Money-Back Guarantee
  • Unlimited US-Based Technical Support

Product Information

Features, Description, Reviews, Q&A, Specs & Installation



The SL183A lens provides an ultra-wide field of view without distortion. The lens incorporates patented Linear Optical Technology® which allows an ultra-wide field of view without barrel distortion found in other wide angle lenses. This design allows increased resolution at the edges of the image thus increasing the probability of detection in security systems.

The SL183A is a high-quality lens designed to allow the installer to take full advantage of the high resolution of HD and multi megapixel cameras. The lens can be used on cameras up to five megapixel resolution giving a crisp image from edge to edge.

This varifocal lens also includes an easy zoom feature which allows the installer to focus the lens once and then adjust zoom or magnification to give the best field of view. Only minor focus optimization is required after zooming, meaning that there is no need for the iterative focus-zoom-focus method of setup required for other varifocal lenses.

The lens is IR corrected for use with true day/night cameras. This IR correction focuses IR light from artificial illumination at the same plane as the visible light allowing the image to remain in focus when the day/night camera switches to night mode. Unlike lenses without IR correction, the night image will not be out of focus when using IR illumination.


More Information
Megapixel 5.0
Weight (lb) 0.2
Focal Length (mm) 1.8 -3.0
Relative Aperture (F-stop) F1.8
Lens Type Varifocal
Lens Mount CS Mount
Lens Iris DC Auto Iris
IR Corrective Yes
Focus Manual
Brand Theia
Warranty 1-Year


File Name File Size File Type
Data Sheet184 KBPDF
Manual270 KBPDF


IP Camera Bandwidth Calculator: Calculate bandwidth or system load for optimal performance of your network IP security.

Covert Compare Tool: Watch our sample videos to see which hidden covert cameras work best for your covert application.

Compare IR & Low Light Tech: See the difference between standard, super low lux, and IR CCTV security cameras.

Compare Lens FOVs: This handy FOV calculator will help you in determining which lens is right for your application.

Compare Video Frame Rates: Use this tool to compare video frame rate settings on video security DVR products.

DVR Storage Calculator: Determine how much storage you will need for your security DVR.

Lens FOV Calculator: Choose from multiple scenarios and focal lengths to find the lens will work for your application.

NVR Storage Calculator: Determine how much storage you will need for your NVR.

System ROI Calculator: Determine your potential losses without a Video Security System and how much you can save.

Voltage Drop Calculator: Calculates the final voltage for each cable gauge.

Volts/Watts/Amps Converter: Calculates either the volts, watts or amps if two of the values are known.