make catalina windows opaque

• My question might have been stupid, but it was serious. :-)
• I do have the system preference set to reduce transparency.
• The issue isn't what the camera shoots, but what shows up on screen. The background shows through the top window.
• I've thought about it more and decided the best solution is just to look at critical images against an opaque black background.

So thanks! Issue resolved.

Sorry, but I didn't find the screenshot. Basically, though, your reference to a shadow sounds spot on. The visibility of the show-through shadow depends on the color and opacity of what's on top, combined with the size, color, and opacity of what's underneath.

You know, it's like scanning a printed page and having to deal with the shadow image of whatever was printed on the other side of the page. Or like dealing with palimpsest in ancient manuscripts. I accept that most folks love transparency. I just want the option to turn it off and go my contrarian way. You know, not "Reduce Transparency," but "Eliminate Transparency."

Apologies to all! I started looking for answers and trying suggestions on this issue about two weeks ago. Then, last week, my left eye was damaged (don’t know how). I had surgery last Friday morning to repair a torn and detached retina.

The surgery went well, but recovery will be gradual. I can speak with confidence about what I saw before the trauma, but now? I’ll do my best, but caveat lector!

I forget the technical term (“focus”?), but essentially I’m thinking about the window whose three upper lefthand dots are lighted up. In point of fact, though, the phenomenon applies to any visible window that has something else behind it.