Counter-argument, this is all correct, but when the application is against shopping mall criminals it will work well enough. Not talking masterminds here

Nothing wrong with that, look up “coffee sock”. It’s used exactly as you describe, except they put this filter down first, then lift it out with the grounds after it’s done brewing. All the other methods mentioned here are valid too, coffee is coffee!

Assuming you have a modern digital camera, check if it has a Bluetooth phone app that lets you download images to local memory. I was able to zoom in and verify focus after my first shots, this was a major help when I tried stars.