Movies run at 24 FPS (frames per second)
High end VR (virtual reality) runs at 90 FPS; below that, it can make you sick.
So, if you're going to "spin", use a spin rate in that range if you're "flashing" images.
So, think of a "timer" with an event interval of around 24 FPS; which is not cpu intensive. And the form will respond to button clicks to stop spins.
.net - Constantly Update Current Time Display On A Windows Form? - Stack Overflow[
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