When you review the technical sheet of a thermal scope or monocular, you will often see numbers like 2.5x-20x. This indicates the device’s magnification range. However, to avoid surprises when you turn it on, you need to understand that these numbers fall into two completely different worlds: Optical Magnification and Digital Zoom.
1. Optical Magnification (The real, native magnification)
Optical magnification is physically determined by the construction of your device’s lens (its size and curvature). It is the "native" magnification you have as soon as you turn the device on (for example, 2x or 3.5x).
Its big advantage: It does not lose any quality. The sensor uses 100% of its pixels to process the image delivered by the lens, offering the maximum possible sharpness, contrast, and definition.
2. Digital Zoom (Software-based enlargement)
Digital zoom does not use the lenses to get closer. What the device’s internal processor does is "crop" the central area of the image and stretch it so it fills the entire screen. It is exactly the same as when you enlarge a photo with your fingers on your phone screen.
Why you should not overuse Digital Zoom
By digitally "stretching" the pixels, the resolution drops dramatically. If you have a standard sensor (384x288 pixels) and apply 4x or 8x digital zoom, the image will become extremely pixelated, blurry, and you will lose the thermal details needed to correctly identify prey or a person.
How do you choose based on your needs?
- If you hunt in stalking hunts or short waits: You want a device with a low base optical magnification (1.9x or 2,4x), as it will give you a much wider field of view to react quickly.
- If you hunt in stalking hunts or open fields at distances over 800m: You need a high base optical magnification (3.4x or 4x) to recognize details at long range natively without having to pixelate the image with digital zoom.
Buying tip
If you plan to use digital zoom a lot, you absolutely need a high-resolution sensor. Discover our latest-generation microbolometer devices in the High-Resolution Thermal Scopes (640x512) section to zoom in without losing sharpness.