: Prefer 1080P or higher . Many budget "Camcom" models claim 4K but actually upscale from 720P.

This is the legal bedrock. Generally, you can film anything visible from a public space (e.g., the sidewalk in front of your house) or from your own property. However, you cannot violate a person's "reasonable expectation of privacy." This includes:

Perhaps the most popular "camcom" device. It functions as a real charger while a tiny lens records HD video. It’s perfect for indoor spaces where a phone charger wouldn't look out of place.

Use portable hidden cameras only in your own home, your private office, or public spaces where privacy is not expected. Always inform household members if possible, except in genuine safety investigations approved by counsel.