Wide-angle and fisheye lenses are marketed as straightforwardly better. They are not better or worse — they trade detail for coverage, and whether that trade is worth it depends entirely on the room.

What the degrees mean

Field of view is the angular width the lens takes in. Roughly:

• 60–80° — similar to a phone's main camera. Covers a specific approach.
• 100–130° — the common security range. Covers a doorway and its surroundings, or most of a small room.
• 140°+ — fisheye territory. Covers a whole room from a corner, with visible barrel distortion at the edges.

The XCAM Air sits at 140°, and pairs it with a 180° rotatable mount — so the lens can be aimed independently of how the body is positioned, which is what makes it easy to place in awkward spots.

The trade you are making

A sensor has a fixed number of pixels. Widening the lens spreads those same pixels over more scene, so everything in frame gets smaller. A 1080P camera at 140° puts roughly half as many pixels on a face at a given distance as the same camera at 70°.

In practice that means wide angle is excellent for answering "what happened and where", and weaker at "who was that" unless the subject is close.

Barrel distortion is real but rarely a problem

Fisheye lenses bend straight lines near the edges — door frames curve, walls lean. It looks odd but costs you nothing for security purposes; the information is still there. Some cameras apply software de-warping, which straightens lines at the cost of cropping the edges slightly.

When to choose wide

• One camera covering a whole room, especially from a corner
• Rooms with multiple entrances you cannot cover individually
• Short distances, where even reduced pixel density is plenty
• Where you cannot mount centrally and need the coverage to compensate

When to choose narrower

• A single approach — a front door, a gate, a till
• Long distances, where you need pixels concentrated on the subject
• Where identifying a stranger, not just detecting motion, is the goal

The practical answer

Two well-placed narrower cameras usually beat one very wide one for identification, and one wide camera usually beats two narrow ones for situational coverage. Decide which you actually need before paying for degrees. The XCAM comparison guide lists the field of view for every model.