After several recent failures I finally managed to track down some brown argus that would keep still enough for me to film.
This is a particularly fresh and well-marked female.
Next a very well-behaved male, keeping nice and still for me.
Then another male turned up even smarter than the first.
I've never noticed the bronze sheen on this species before.
Once they get a bit tatty the males can resemble female common blues quite closely.
The best way to be certain you've got a brown argus is to check the single black spot in the centre of the underneath of the front wing.
Common blues have several spots here.
You can just about see it on this sequence of a female brown argus.
There were a few common blues here as well.
This female shows well all the differences between the two species.
Finally a male common blue appeared, a bit old but still with a particularly bright blue body.