[baybal2]

My favourites are the liquid crystal lenses. Essentially they are micron scale Fresnel lenses controlled by electric field. No moving parts, very thin, ideal for something like a camera module.

I'm surprised that nobody managed to commercialise it in that niche yet.

[zeristor]

Do you have a link for that? They have used holographic optical elements to make shorter SLR lenses, although I don't think the image quality was excellent, but if they went to the trouble it must have been fairly good.

[dekhn]

doesn't really seem commercial grade yet: https://www.imaging-resource.com/news/2015/10/05/this-smartp...