Superboy while living in Smallville. Of course he wasn't even trying. Not only was his costume jeans and a tee-shirt while his disguise was jeans, a flannel shirt and glasses, he couldn't even be bothered to remember to actually wear the glasses more often than not.
The face vibration thing was a hoot. First, if you vibrated so fast to blur a standard camera, people couldn't see your face. Sure, maybe you only did that when a camera was pointed out you but look how they got the shots of the UK princess - very far away. Sure, Flash or Supes scans a 360 sphere constantly - whatever.
Second - modern stuff can beat vibratory rates that are very, very high. You would almost have to vibrate at FTL. That would be noticeable.
Just don't disbelieve. You would need GL tech to construct camo at extreme level.
I think Christopher Reeve proved that the Superman disguise isn't all that silly. Just look at it:
Now remember how different Revee played Superman and Clark Kent, and imagine that in real life. Who would believe the goofy Clark Kent was in fact Superman? Nah, he just looks a little like him.
One could even say it would be the same as saying this two are the same man:
A bit of a tangent... because its Marvel rather than DC... and long, long ago.
But Johnny Storm didn't admit to being the Human Torch for a short while in the very early days of Marvel. (See early issues of Torch solo series). This was against the background of the other three members of the FF not having secret identities, and it being well know which 4 people had been on the fateful rocket ride!
After very few issues it was realised how daft it was. And when John Boy told all his friends, the reaction was "Yes. We knew all along, but pretended we didn't so you wouldn't be upset".
Clark can destroy that with his heat vision.Second - modern stuff can beat vibratory rates that are very, very high. You would almost have to vibrate at FTL. That would be noticeable.