You can do this hike in a day, but I chose to camp so that I could catch the sunset and sunrise without having to get up at silly o'clock. I parked at Le Chazelet to the east of the lakes as that provides the easiest access up to the Plateau.
I camped at Lérié and watched the sunset from this spot. The light was directly on the Meije at sunset so rather flat, so I waited around for the light to hit after sunrise the next day before moving on to Lac Noir, and returning home.
Out of the two lakes, Lac Noir is the larger and more popular, but Lérié has a low rock wall that lets you see the mountain range beyond - and with good weather the reflections are superb!
Stats: 17km / Gain 1,100m / Max 2,460m