Minimum spec? — 1 Answer

- Minimum: 2000
- Average: 2000–2300 (tubes often exceed the minimum, with many in the 2100–2200 range for optimal balance of clarity and low-light sensitivity)

- Average Resolution: 64–72 lp/mm (center resolution; higher values provide sharper detail, and values above 64 are generally indistinguishable in practical head-borne use)

- Signal-to-Noise Ratio (SNR):
SNR is the most critical spec for low-light performance, indicating how well the tube distinguishes signal from electronic noise.
- Minimum: 28
- Average: 28–32 (higher SNR enhances image clarity in very dim conditions, with Mil-Spec tubes prioritizing this over raw FOM)