Senanque Abbey is one of the always-seen places to photograpgh lavender; although maybe not the best it's worth going there. We went when we arrived but because of the late, damp Spring (yes,even in Provence!) it wasn't ready! On returning at the end of our week it was looking much better, though still not the striking purple it would be in the coming week. I will put up others with which shows the vibrancy when in full colour.
Thanks for looking