I have written often about my absolute ignorance when it comes to art. Nevertheless, I have enjoyed several movies on the subject, including documentaries like “My Kid Could Paint That” and “Made You Look,” as well as fictional stories like “The Last Vermeer” and “The Burnt Orange Heresy.” All of them, in one way or another, center around questions of authenticity — was the painting really created by the famous artist it is credited to?

The most recent of these is another documentary, “The Lost Leonardo,” about a piece da Vinci may or may not have painted, “Salvator Mundi.” It was unearthed in 2005 by two collector/dealers who bought it for a mere $1,175 from someone who obviously didn’t know what they had. Those dealers later sold it for tens of millions, only to see it later bought — in 2017, probably by Saudi Prince Mohammad bin Salman — for $450,000,000, the highest value ever placed on a painting.

Is it really that valuable? Was it really painted by da Vinci? Director Andreas Koefoed interviewed art experts, dealers, curators, financiers, journalists, and others — including Dianne Modestini, who did so much restoration work on the 500-year-old piece that many argue it’s more hers that Leonardo’s. Koefoed also  spends quite a bit of time with Yves Bouvier, a wheeler-dealer who at one point bought “Salvator Mundi” for $83 million, then sold it the next day to a Russian oligarch for $127 million (that’s quite a markup!).

Like many of the other art movies, I kept shaking my head while watching “The Lost Leonardo.” Not because it isn’t riveting — it is — but because of how the subjectivity, greed, and hype (like giving “Salvator Mundi” the nickname “The Male Mona Lisa”) of everyone associated with that business can create a phenomenon and drive its price up and up and up.

“The Lost Leonardo” ends up with more questions than answers. In doing so, it offers yet another revealing portrait of the art world.

I give it an 8 out of 10. It will be on my Best Documentaries Of 2021 list. Opens today, appropriately, in arthouse theaters.