How did Richard Avedon light the picture of Monroe?

[distantgalaxy]

What type of lighting/how did Richard Avedon light this picture of Monroe?
I can't find any concrete information on this anywhere.

Richard Avedon: Marilyn Monroe, Actress, New York City (2002.379.11) | Heilbrunn Timeline of Art History | The Metropolitan Museum of Art

 

[2WheelPhoto]

I tried to figure out his methodology too because I like how he broke all the rules most of the time. This helped me understand it:

Fashion photography paid the bills, but it was portaiture that Avedon found the most deeply satisfying. In the 1950s, he began taking studio shots of famous people from all manner of fields, including actors, writers, politicians, and other celebrities. The Avedon portraits were done in a very distinctive manner, primarily using a large format 8x10 camera on a tripod. Avedon posed his subjects directly facing the unblinking eye of the camera against a plain background. It was as if the camera was peering into the very soul of the subject, and exposed the character of the portrait subject, flaws and all. The pictures have been likened to mug shots in their unvarnished directness (this is not to say that they were unretouched, however, as Avedon was known for retouching the images, work that was often done by one of his many studio assistants). The famous minimalist black and white portraits were remarkable for their ability to reveal something private about well-known but distant public figures. Avedon described his approach to photography in this way, “I've worked out a series of no's. No to exquisite light, no to apparent compositions, no to the seduction of poses or narrative.”

 

[Helen B]

Although they look like studio images, a lot of Avedon's iconic portraits were taken on location. He had white background paper taped to a wall in the shade and took the portraits in front of that - quite flat, shade lighting.

Of course this portrait of Marilyn wasn't done like that, but the approach to lighting looks similar, and similarly simple, as 2WheelPhoto mentioned. As you can tell, though very soft, it has slight directionality - from the photographer's left and slightly raised above camera level.