For the benefit of anybody else using that outdated document, the only change required is

channel=0

instead of channel=1

I have long been using the snapshot api, and recently discovered the width= and height= parameters to reduce the retrieved image size (and thus reduce bandwidth).

For example, from an RLC-840A, the following works to get a 640x360 snapshot, which is about 32KB, compared to the full-size snapshot at 670KB

https://[camera-ip]/cgi-bin/api.cgi?cmd=Snap&channel=0&user=guest&password=[obfuscated]&rs=000000&width=640&height=360

However, when I try to reduce the dimensions further, below 640x360, the camera always returns a 640x360 image.

I know I can rescale the image again at the browser, but is there a way to make the camera itself return a smaller image? I'm putting together a page with a dozen thumbnail snapshots that auto-refresh every 2 seconds, and it would be nice to have the camera return 160x90 snapshots directly and minimize bandwidth.

For the benefit of anybody else using that outdated document, the only change required is

channel=0

instead of channel=1

I'm trying to get a snapshot from a newly-installed RLC-520A using the CGI guide downloaded from the Reolink website.

The camera returns an empty response with a 404 status code.

According to the guide, the URL should be

http://[ip-address]/cgi-bin/api.cgi?cmd=Snap&channel=1&rs=000000&user=guest&password=[redacted]

I've created the guest user, and can verify the the camera recognizes the user because providing the wrong user and/or password returns

    [
   {
      "cmd" : "Snap",
      "code" : 1,
      "error" : {
         "detail" : "invalid user",
         "rspCode" : -27
      }
   }
]

However, with the correct user and password, the response is a completely empty (0 data length) response with a 404 status code, as confirmed in the browser network console.

So, what is the correct URL syntax to retrieve a snapshot?