https://uploads.tapatalk-cdn.com/201...a39c33d162.jpg

Here's the view out the back of my car. Notice the direct view of can't see the hood of the car behind me but in the fresnel lens I can see the headlights.

I know I'm about 18" from the car behind me when I can only see the hood and not the lights.

Works great for parallel parking.

https://www.icloud.com/sharedalbum/#B0SJHciePGwhZcU

I took pics of how I made it. Take note of the example photo with my bright red Thermo Pen in the foreground and tiny through the lens.