Part 3 — Understanding Tube Specifications
How to read a tube data sheet and interpret the specifications that describe real-world image quality.
- Lesson 1: Reading a Tube Data Sheet
A practical walk-through of the serial-specific inspection record that tells you what an image-intensifier tube measured.
- Lesson 2: Signal-to-Noise Ratio
Why SNR is one of the most important image-quality metrics.
- Lesson 3: Center Resolution
How sharply a tube renders detail in the center of the image.
- Lesson 4: Figure of Merit
What FOM is, how it is calculated, and what it summarizes.
- Lesson 5: Equivalent Background Illumination
How EBI describes the inherent noise floor of a tube.
- Lesson 6: Halo
The diffuse ring surrounding a bright source and what creates it inside the tube.
- Lesson 7: Gain
How much a tube amplifies light and why more is not always better.
- Lesson 8: Photocathode Sensitivity
How effectively the tube's input surface converts available visible and near-infrared light into an electrical signal.
- Lesson 9: Fixed-Pattern Noise
Why a stationary mesh, honeycomb, or other repeating structure can appear across the image—and how to separate it from random noise, ordinary blemishes, optical contamination, and damage.
- Lesson 10: Comparing Specifications in Context
How to weigh tube measurements together, account for the complete system, and stop pretending one large number answers every question.
- Lesson 11: Why Higher FOM Is Not Always Better
Why a higher Figure of Merit is generally desirable but does not automatically identify the best tube, device, or value for every application.