Base magnification
How much bigger things look before any digital zoom, like 2× or 4×. Higher is not automatically better: it narrows your view.
What it means
Base magnification, or native magnification, is how much larger the device makes things look at its widest setting, with no digital zoom. It comes from the lens, the sensor’s physical size and the eyepiece and screen together. Hunting thermals range from about 1× to 6×, with most between 2× and 4×. A few very wide units go below 1×.
What it changes in the field
Base magnification is the setting with the most real detail. At this level every sensor pixel is used, so it is where you should identify animals. Any zoom past it only enlarges pixels (see digital zoom).
Higher base magnification makes an animal look bigger, but it also narrows the view. A 4× or 5× unit can feel like looking through a straw when you scan a field for coyotes. A low-power unit is easier to scan with and to find animals that come in close.
A common pattern: under about 3× for a handheld scanner, and on the rifle, something close to the magnification you would use on a day scope for the same shots.
Why a bigger number can mislead
Base magnification is not a measure of detail. Put a 640 sensor behind the same lens as a 384 and the base magnification goes down, because the larger sensor sees a wider area onto the same screen. Yet the 640 shows the same detail on the animal and more ground around it. Compare pixels on target instead.
What to look for
Read base magnification with field of view. Choose the view you need for how you hunt, then compare detail with our calculated numbers. We show the maker’s figure but do not score it.