4 x ESP32 boards compared, all with an OV2640 camera module:
https://www.youtube.com/watch?v=5IhhyJjjCxo 

Possible applications? I’ve been looking at the cheapest way to add video to train layouts with at least 2 goals, if not more:

• Video-based train automation.
• In-car video streaming.
• Single/multi view on remote monitor. E.g. monitor hidden staging yard(s) or tunnels, or display activity on a remote monitor -- any place where there’s motion.

For each of these, my concern is footprint, price, and power. Each time I operate under the expectation I can offset any processing to a local laptop or tablet or similar.

For example, for streaming the expectation is that the camera can either send a constant stream and the computer does motion detection, or the camera can do basic detection and only transmit when there are changes. A mix is possible (e.g. non-sophisticated change detection on the camera, then a better filtering at the computer level).

In this case, the value of the ESP32 is fairly reduced. It only needs to act as a crude frame server. The benefits are a small footprint, and real 1080p or better.

The contenders are mini pinhole wifi cameras like the one I tried earlier. This would be an almost ideal choice if it were really a 1080p and not a marketing gimmick using a fairly old 720p @ 30 Hz.