I noticed this also (the subtle blinking) and thought it was a defect. I contacted Arc and Peter told me to send it back, so I did. I called Arc today and they said it shouldn't blink, and that they didn't program it that way. The woman I spoke with at Arc said that the one she was looking into did not blink with the RFS option turned on. But if you just hold your hand around the lens, you probably won't see it. The thing is, I don't know if Arc is really aware of this, I only noticed it in a room so dark that if I held my hand in front of my face, I couldn't see it, and even then I had to look directly into it. My girlfriend had to watch it for 4 or 5 blinks before she could even see it.