Taxi from the 14th to the 10th info
 

I suppose there might be cabs nearby the Atelier des Lumières tooling around figuring people might be exiting the exhibit looking for one, but it's not the kind of neighborhood where cabs would likely just be roaming around. But, you can walk up to the Blvd. de Belleville and likely find one (about a 10-minute walk, mostly uphill) or call a G7 to come pick you up (you'll pay a small fee for that).

Have you looked at the municipal bus lines?

Most of the bus lines around there are more east-west. I don't know if you literally want to go to the St Michel metro stop or what, but there is bus 69 which goes right by there (on rue du Chemin Vert going back across the city) and then goes over to the Louvre and the Musee d'Orsay and finally Champ de Mars. There's a stop at Chemin Vert and ave Parmentier. So if going to visit any of those appeals, that would be a good idea. That's the famous bus Rick Steves touts as a "free" or cheap bus tour of the city or something like that.

There is a taxi stand at place Leon Blum, also, where the Voltaire metro stop is, but I wouldn't count necessarily on taxis waiting around there. There is a callbox also, although I've not had good luck with those, although that was only one time I tried (just no cab could come, they were too busy).

What about Uber?

In January from that same hotel to L' Atelier des Lumières we used uber in both directions. Yes, your US account works just fine in Paris- we used it extensively, were quite satisfied..

I suppose we were lucky, but last year we got a taxi ride very near to the Atelier des Lumieres. This year, I do plan to use the bus OR Uber from there. The G7 works well, too, if you have a way to call or can borrow someone's cell phone. Enjoy the show !

We went last year from the same left bank area by cab and we only paid around 15 euros I think. It was easy to get a cab right out front after because people were arriving by cab. I also was with someone who didn't walk well but the bus would have been fine too although we were in a time crunch for a dinner reservation, so took a cab. Also, just in case you aren't aware of it, there is really no place place to sit down inside the Atelier des Lumieres , so people sit on the floor or on the bases of support beams so that can be challenging for some folks getting up and down.

Bonjour from Paris! We went last Friday, the Van Gogh show was quite good, as was the Japanese feature. As kerouac has noted elsewhere, there ARE seats, but they are in the little cafe/bar which offers only a smaller scale version of the show, not the full immersive experience. .