The correct spelling, Stieglitz, is perpetually ignored by IMDb with the exception of a few comments that reveal some knowledge about German pronunciation. I would like to think that a correction will be made rather than compounding ignorance. The website Wikipedia has a very good bio on Stieglitz, and surprisingly supports the story line of the movie. Iron's appearance is strikingly close to Stieglitz's own face. So often film writers use "poetic license" to bend a real story to one they feel has greater interest. It is interesting that strong willed women gravitate to New Mexico. Millicent Rogers, a well known patron of the arts, left a large imprint on the Santa Fe/Taos axis. Rogers deserves a bio herself.
Review of Georgia O'Keeffe
