weird reverse LED?

[dentaku]

I recently tested out some pink lensed red LEDs from an old Pioneer stereo and at first I thought they didn't work but then I realised that they are simple backwards LEDs.
What I mean is that looking inside the lens you can usually tell the anode from the cathode of a regular LED (thin bit and thick bit) but this one was the other way around.

Does/did this happen alot? You'd think that LEDs have been standardized for many years now and a stereo from the 90's would have LEDs that are all the same.
By the way, these are horribly dim red LEDs. One has a concave conical lens and the other pink one is just regular shaped but they're both backwards.

[mikerj]

This is fairly common with more modern LEDs, you can't reliably tell just by looking through the body any more. 

[T3sl4co1l]

LED pet peeves:
- Which lead is the cathode?  The shorter?  Yeah, triple-check the datasheet on that one.
- Which lead is the cathode, the thicker one (internal view; the one the die is mounted to) or what?
- Round LEDs with flats (which side!?)
- Round LEDs without any flats
- Bicolor LEDs with three leads and any of the above concerns
- SMT (chip) LEDs, with
- Microscopic or invisible polarity markings,
- Or markings that are completely wrong (dot means..?)

Let's not even start with other optoelectronics, like LCD module pinouts... 

Tim

[dentaku]

I guess people with more experience than me have seen it all.