Hey guys, I get repeated questions about how big the shield should be and proportionally how big the star should be. First a disclaimer. I have never personally seen or examine a movie shield. I know Chris Fields has. And he may have additional opinions. So, I'm basing this on what I have heard from people who have seen it, dimensions given for the auction of the screen-used shield, and primarily .... my own discernment of what looks "correct" to me. Your milage may vary
So, my shields are a 25" diameter shield with a 10" diameter center circle. Each of the three rings is 2.5" thick. For me this got damn close to the proportions of the movie shield. I also chose a 25" shield cause I ain't that big. The movie used both 25" and 26" shields. Below is a link with this info, and also an image that shows this proportionally.
Hope this helps.