Shooting slow motion for music video and sync

[Marc Hutchings]

Hoping for a quick answer- have a music video shoot, want to shoot faster fps and slow it down in post. Retimed song to 200% 50fps for a 25fps delivery but it's so fast I don't think the singer has much chance of lip synching correctly. 150% sounds manageable but that's works out to 37.5 fps not sure the complications of retiming that afterwards??? Any advice greatly appreciated which speed works well for a 25fps delivery?

 

[Akin A]

If some of the artist's words are very fast at a normal speed, u can cut away to something else during those words/lines.

 

[Marc Hutchings]

Yea I did consider that but it's pretty much the whole chorus which would be a problem, is there a slower speed which would work well? What speed do you guys use?