There are several readers asking how this works. I use the same setup the OP has shown in his last photo. The camera is connected to a lens that is mounted to a gimbal head via its tripod bracket. I have a 400mm and 600mm that I can use this with. The U bracket is mounted to the bottom of the camera and the red-dot to the top of the bracket. The bracket is adjustable in the vertical direction.
At the shooting site, after things are assembled, you fine tune the red-dot to match the center of the viewfinder. You can now sit back from the camera and use the red-dot to pinpoint the camera to the target while both eyes are viewing the scenery. A great setup for BIF when using the gimbal.

I couldn't find anything regarding this, so I thought I'd ask here. I have thousands of color prints dating back to the 1960's. Like a lot of folks, I took lots of shots, hoping to get one that came out good. And like lots of folks, I kept all of them, many of which, no doubt aren't really worth keeping. My wife has suggested that we go through these pictures, keep the ones we want (for the memories) and toss the rest. My question is, what is the best and most efficient way to do that? Can I use the scanning feature on my printer to scan them into the computer or are there programs or other devices that do this? This is going to be a gigantic project. Thanks in advance. And please, no "you should google it and not bother us" responses. Just looking for some good advice here.