When you sand the end of a clear LED then ambient light makes the sanded spot look bright even when the LED is turned off.

 

When you sand the end of a clear LED then ambient light makes the sanded spot look bright even when the LED is turned off.

Not on mine. The end is dull and doesn't reflect ambient light. It just acts as a "screen" that the projected red light from the LED shows on. I'll see if I can get a representative picture.

 

Here are some pics showing:

The basic schematic, each of the four LEDs draws about 500 uA.

The meter face shows the four LEDs run across the top set of range switches with no power on. The sanded down faces off the LEDs look a kind of dull light gray, but that's from the flash. Under normal room light, they not noticable you just see just see the center pad where the die is through the dull flat lense.

With the power on (on viewing axis) the red LEDs are super bright, brighter than the LED digital display to the left that has about 10 mA current per segment.

Note the small green LED to the right of the four super bright reds. It has about 15 mA in it, supplied by the external battery charger. But it is a "standard" brightness LED.

Note the picture about 45 degrees off axis shows the red LEDs are still very bright.

 

Here's a good picture of what they look like when not illuminated.

Wow... I really need to dust the range buttons on that thing.

 

Yes, your "super bright" LEDs are nice and bright with a current of only 0.5mA and their face sanded for wider dispersion.