5 ms·

Can one power up the camera for only a few milliseconds? Enough to take a still photo, without the LED getting bright enough for a human to notice?

Wowfunhappy 6y ago
No, because the LED doesn't need nearly as much power as the camera. And it takes the camera more than a few miliseconds to start working.
- xxs 6y ago
  > much power as the camera You mean current, right? And it'd have current limit circuit, at a resistor but likely a slow start circuit entirely? Unless you share the schematics, it's an empty argument.
smsm42 6y ago
It doesn't have to be milliseconds. Most of people don't sit and stare on the camera all day. I have multiple displays and turning camera for a second when I am looking at another display - or even the laptop one but concentrating on something on the screen, especially the lower part - would slip my attention very easily. Or I might notice something off with peripheral sight, but it is very inexact and while I turn my head to bring it into the field of sight where I have a good resolution, it could be already gone. Of course, the cover has none of these problems. If it's covered, then it's covered.
shakna 6y ago
In the past, this was exactly how it was done. Here's an article on the FBI doing it with an Apple webcam six years ago [0]. Should be noted that was after Apple went to the effort of making a hardware delay to try and force the LED to turn on first, but it was still worked around. [0] https://www.smh.com.au/technology/researchers-activate-apple-isight-webcams-without-warning-light-20131219-2zmy4.html https://www.smh.com.au/technology/researchers-activate-apple...
saagarjha 6y ago
This used to be a thing, where you’d flash the LED briefly and hope the user didn’t notice. But new Macs prevent this by having a minimum duration the light will remain on.
- dahfizz 6y ago
  Hm, seems like the LED has some logic to it and isn't just connected directly to the camera....
- jordan314 6y ago
  FWIW I tried using the command line utility isightcapture on my 2019 macbook, and the LED turned on for 4-5 seconds and I got a dialog asking if I wanted to allow access to the camera. So this seems to be true. I still have a camera cover though

Wowfunhappy 6y ago

No, because the LED doesn't need nearly as much power as the camera. And it takes the camera more than a few miliseconds to start working.

xxs 6y ago
> much power as the camera You mean current, right? And it'd have current limit circuit, at a resistor but likely a slow start circuit entirely? Unless you share the schematics, it's an empty argument.

smsm42 6y ago

It doesn't have to be milliseconds. Most of people don't sit and stare on the camera all day. I have multiple displays and turning camera for a second when I am looking at another display - or even the laptop one but concentrating on something on the screen, especially the lower part - would slip my attention very easily. Or I might notice something off with peripheral sight, but it is very inexact and while I turn my head to bring it into the field of sight where I have a good resolution, it could be already gone. Of course, the cover has none of these problems. If it's covered, then it's covered.

shakna 6y ago

In the past, this was exactly how it was done. Here's an article on the FBI doing it with an Apple webcam six years ago [0]. Should be noted that was after Apple went to the effort of making a hardware delay to try and force the LED to turn on first, but it was still worked around. [0] https://www.smh.com.au/technology/researchers-activate-apple-isight-webcams-without-warning-light-20131219-2zmy4.html https://www.smh.com.au/technology/researchers-activate-apple...

saagarjha 6y ago

This used to be a thing, where you’d flash the LED briefly and hope the user didn’t notice. But new Macs prevent this by having a minimum duration the light will remain on.

dahfizz 6y ago
Hm, seems like the LED has some logic to it and isn't just connected directly to the camera....
jordan314 6y ago
FWIW I tried using the command line utility isightcapture on my 2019 macbook, and the LED turned on for 4-5 seconds and I got a dialog asking if I wanted to allow access to the camera. So this seems to be true. I still have a camera cover though