Weak IR LEDs

Using Arduino LEDs and Multiplexing
7

Well, the circuit works. The camera shots a picture every 2 seconds.

Here's the sketch:

////////////////////////////////////
// Simplest test. IR + Canon camera
////////////////////////////////////

int pin8 = 8;
 
void setup()
{
  pinMode(pin8, OUTPUT);
}
 
void loop()
{
  /* ----- shutter! ----- */
  for(int i=0; i<16; i++) 
  {
    digitalWrite(pin8, HIGH);
    delayMicroseconds(11);
    digitalWrite(pin8, LOW);
    delayMicroseconds(11);
  } 
   
  delayMicroseconds(7330); 
   
  for(int i=0; i<16; i++)
  { 
    digitalWrite(pin8, HIGH);
    delayMicroseconds(11);
    digitalWrite(pin8, LOW);
    delayMicroseconds(11);
  }
  /* ----- end shutter ----- */
 
 delay(2000); //2seg
}

And here's the circuit as it is now:

I've tried without the resistor. Without the switch. Without both. With the resistor after the switch. Bigger resistors. Smaller ones... All of these tests worked, but the distance seems to be approximately the same.