I’ve finally got my garadget installed, yayy! I am wondering about one thing though. I understand that one should never stare into the laser emitter directly. However, when garadget and the reflector are installed, is it safe for people to stare into the reflected laser off the reflector? It would definitely attract attention and invite people into looking at it. What if someone goes up to the garage door, very close to the reflector and look at the reflected red dot?
I am not an expert here, but have worked with several lasers of significantly higher power than that in the Garadget over a few decades. The reflection off the tape is not like that from a mirror. It is diffused and the portion of the original laser beam that reaches any observer’s eye will be significantly reduced in power. The amount of that reduction is very likely to be related to how far off angle the observer is from the original beam.
It should be quite safe to observe the reflection when the dot is as little as a foot or two overhead. I would not recommend trying to observe it up close and with the laser very close behind the observer’s head. It is likely to still be safe, but the chance of having a highly reflective bit of tape at just the wrong spot is not a chance worth taking in my opinion.
As Bob pointed out, the main property of retro-reflective material used on the door is that it sends the majority of light back to where it came from. Unless you are looking from exactly behind the Garadget, the light intensity of the dot you are seeing is very low. Additionally the laser is low power and activated for very short period of time.
If you ever have the urge to look directly at a red laser because it’s irresistible, after you get your eyes treated go ahead and get your mind treated at a local mental health facility. Looking directly at a laser is equivalent to touching a hot stove and only mentally challenged would ever do that.
Regardless if exposure is intentional or accidental, the laser safety is a valid concern and we can not ignore it.