How to Identify a Spider by Photo (Get the Angle Right)

• Top-down angle: shoot the spider's back, where the diagnostic markings are
• Focus beats closeness: use zoom or macro mode rather than pushing the lens at it
• Light it: daylight or your phone flashlight from the side; direct flash blows out the pattern
• Include the legs: leg posture and banding are secondary field marks the AI uses
• If it is in a web, photograph the web too; web architecture narrows the family instantly

Identification models weigh the dorsal pattern, body proportions (leg-to-body ratio, abdomen shape), leg banding and spines, eye arrangement when visible, and posture. Web type adds strong context: orb webs, funnel webs, cobwebs, and no web at all each point to different families.

The output is a species match with a danger verdict. Sanity-check it against location: a species that does not occur in your region means rescan with a better angle.

Most failed identifications come from three photos: the blurry ceiling shot from two meters below, the side-angle shot that hides the back pattern, and the flash close-up that turns the spider into a white blob. Each has the same fix: stabilize, get above the spider or wait for it to be on a flat surface, and use indirect light.

You can identify a dead spider or one trapped under a glass just as well, often better, since it holds still. If you are collecting it for identification anyway, slide paper under a clear glass; you get a perfect top-down view through the glass and the spider gets released after its portrait.