Thanks for the reply!
But, actually I wasn't talking about that. We can deal with the 150ms for medium resolution. The problem isn't the find circular targets VI - it's with the Get Image VI. This takes up way more than it should according to the FPS we set. It has a wait function inside that sometimes waits for over 200ms to get new info from the camera! Did you check how much time it takes your whole vision processing VI to execute?(not just the find circular VI)