FAQ

WHAT IS FOM?

Figure of Merit (FOM) is the industry-standard scoring system for image intensifier tubes. It's calculated by multiplying line pairs per millimeter (resolution) by the signal-to-noise ratio. Higher FOM generally means a sharper, cleaner image in low light. Modern Gen 3 tubes typically score between 1800 and 2400+. FOM is the most cited spec when comparing tubes, but it's not the only thing that matters. Phosphor type, blemish patterns, and EBI also affect the real-world experience.

WHAT IS GAIN?

Gain is how much the tube amplifies incoming light. Higher gain means a brighter image in dark scenes, but past a certain point more gain just adds noise and washes out detail. Most modern PVS-14s have adjustable gain so you can dial it to the conditions you're operating in. Tube spec sheets list gain in cd/m²/lx. Typical numbers run from 30,000 to 70,000.

WHAT'S THE DIFFERENCE BETWEEN GEN 2+ AND GEN 3?

The headline difference is the photocathode material. Gen 3 tubes use gallium arsenide (GaAs), which is dramatically more sensitive to near-infrared light, the wavelengths where most ambient night light actually lives. Gen 2+ uses a multi-alkali photocathode that's less sensitive in those bands.

In practice: Gen 3 sees deeper into darkness with less visual noise. It also tends to have higher gain, better signal-to-noise ratios, and longer operational life. The trade-off is cost. Gen 3 tubes run substantially more. Gen 2+ is still a real, capable image intensifier and works fine in moderate ambient light. For true low-light work, Gen 3 is the standard.

DO YOU SHIP INTERNATIONALLY?

No. All sales are domestic US only. Image intensifier tubes are export-controlled under ITAR (International Traffic in Arms Regulations), and shipping them outside the US without a State Department license is a felony. I'm not set up to navigate that process and won't risk it. If you're outside the US, look for a domestic builder in your country.

HOW LONG DO BUILDS TAKE?

It depends on what you ordered. Prebuilt units listed as Available on the inventory page ship within a few business days of payment clearing. Custom builds take longer. Typically 2 to 6 weeks depending on what parts I need to source. Tube sourcing is the biggest variable; some are common, some take weeks to find at the right price. I'll give you a realistic timeline when we confirm the spec.

CAN I SELL YOU PARTS OR TUBES?

Yes. I'm always open to new sources and business contacts. If you have tubes, housings, or related parts for sale, hit the contact page and tell me what you have, your asking price, and any documentation or spec sheets. I respond to legitimate offers within a day or two.