Introduction

Choosing the right lens is one of the most critical steps in building any camera system. With hundreds of lenses available, mismatched mounts, incompatible sensor sizes, and incorrect focal lengths can lead to blurry images, dark corners, wasted time, and costly redesigns. Engineers, buyers, and system integrators often struggle to sort through technical specifications to find exactly what their project needs.

At Towin, we designed our customized lens search tool to solve this problem. Our powerful product filter allows you to search lenses precisely by mount, sensor size, effective focal length (EFL), and other key parameters. In this guide, we break down how to use our filter efficiently, explain core lens parameters, and show you how to select the best lens for your application in minutes.

Customized Lens Search

Why Use Towin Customized Lens Search?

• Avoid compatibility errors between lens and camera
• Save time by filtering only matching lenses
• Speed up project development and sampling
• Match lenses to real-world application needs
• Access professional-grade specs for industrial and commercial use
• Easily compare lenses with the same critical parameters

Core Filter Parameters: Mount, Sensor, and EFL Explained

1. Lens Mount – The Foundation of Compatibility

The mount connects the lens to the camera body. A mismatched mount makes proper installation and focusing impossible.

2. Sensor Size – Avoid Vignetting and Dark Edges

The lens image circle must fully cover your camera sensor. Using a lens designed for a smaller sensor causes vignetting.

Common sensor sizes:

• 1/4″, 1/3″, 1/2.5″, 1/2.3″, 1/1.8″, 1″, and larger

Rule of thumb:

• Lenses for larger sensors work on smaller sensors
• Lenses for smaller sensors DO NOT work on larger sensors

3. Effective Focal Length (EFL) – Control Field of View

EFL determines how wide or narrow your camera’s view is.

• Short EFL (1mm–4mm): Ultra-wide angle, security, panoramic
• Medium EFL (4mm–25mm): General-purpose, surveillance, industrial
• Long EFL (25mm+): Telephoto, long-distance monitoring, inspection

Other Important Filter Options on Towin

• H.FOV: Directly set horizontal field of view
• Resolution: 1MP, 2MP, 5MP, 4K, 8K+
• Iris Type: Fixed, manual, auto iris, P-iris
• F-Number: Low F# for low light, high F# for bright environments
• TTL: Total length for compact designs
• Features: IR corrected, IP67 waterproof, wide temperature (-40°C~85°C), distortion control

Step-by-Step: How to Use Towin Customized Lens Search

1: Select Mount & Sensor Size First

Start with the two most important compatibility parameters to filter out mismatched lenses immediately.

2: Set EFL or FOV

Choose your desired focal length or field of view to match viewing distance and coverage area.

3: Add Application-Specific Filters

Select resolution, iris type, F-number, TTL, and special features such as IR correction or waterproofing.

4: Review Filtered Results

Browse matching lenses, check datasheets, compare specs, and request samples.

5: Request Custom Lens Support

If no standard lens fits your specs, contact Towin for custom design.

Lens Filter Quick Selection Flow Chart

Lens Selection by Industry Use Cases

Security & Surveillance

• Mount: M12 / CS-Mount
• Sensor: 1/3″, 1/2.8″, 1/2.5″
• EFL: 2.8mm–12mm
• Features: IR corrected, low F-number, auto iris

Automotive & In-Vehicle Systems

• Mount: M12
• Sensor: 1/2.5″, 1/1.8″
• EFL: 1.8mm–8mm
• Features: IP67, -40°C~85°C, shock resistance

Industrial Machine Vision

• Mount: C-Mount
• Sensor: 1″ and above
• EFL: 8mm–50mm
• Features: High resolution, low distortion

Drones & Action Cameras

• Mount: M12
• EFL: 1.2mm–3mm ultra-wide angle
• Features: Small TTL, lightweight, high resolution

Lens Selection Tool

FAQs

Q: What happens if mount and camera do not match?

A: The lens cannot be installed correctly, leading to focus failure and unusable images.

Q: Can I use a C-Mount lens on a CS-Mount camera?

A: Not directly. You need a 5mm adapter ring to adjust flange distance.

Q: What does IR corrected mean?

A: IR corrected lenses focus visible and infrared light (850nm/940nm) at the same plane, ensuring clear night vision.

Q: How do I choose EFL for long-distance monitoring?

A: Use longer focal lengths to narrow the field of view and magnify distant objects.

Q: What if I need a special lens not in your catalog?

A: Towin supports fully customized lens design based on your mount, sensor, EFL, FOV, size, and environmental requirements.

Conclusion

Finding the right lens no longer requires hours of manual searching. With Towin’ customized lens search filter, you can quickly filter by mount, sensor, EFL, and other critical parameters to find compatible, high-performance lenses for any vision system.

Whether you need standard lenses or fully custom designs, Towin provides reliable optical solutions for security, automotive, industrial, drone, and IoT applications.