Austraila's Round 50 cent coins

[trout]

The double bars are pretty faint though.

Virtually every 1966 50¢ I have looked at has some sign of double bars. The question is how pronounced do the bars have to be to call it a proper double bar rather than just a pretender?

This is a bit "off Topic" but has anyone noticed that the 50c Proof coin in the 2015 50.50 two coin set is a very definite double bar .