...how very important it is to take advantage of seeing art first-hand, as opposed to relying on reproductions of it either online or in books....
Reproductions of Sargent’s Tent in the Rockies suggest something of the artist’s masterful use of transparent watercolor, but the reproductions do not nearly capture the luminosity of paintings like Tent in the Rockies. When Sargent captures the quality of anything white, he infuses the exposed white watercolor paper [the part that he does not paint at all] with whispers of delicate shades of yellow ochre, blue, and burnt sienna. Because of the luminosity that he captures, his predominantly white paintings, like Tent in the Rockies, scream from their places on the wall.
In the reproductions of Tent in the Rockies, you see nothing of the bits of color that Sargent masterfully lays to suggest the tent’s birch tree poles, and you do not fully realize that the artist only suggested the gear inside the tent with nothing more than a few dabs of perfectly-placed color. Even when seen in person, the gear inside the tent has no detail at all; yet, a viewer’s eyes speculate into form from the suggestions that they see in the pools of color.
(http://www.jackikellum.com/john-singer-sargents-luminous-watercolors-and-winslow-homers-painted-stories-a-discussion-of-the-exhibition-american-watercolor-at-the-philadelphia-museum-of-art/)
Sargent began many of his watercolors with careful pencil drawings that laid out the overall composition of each picture. If you look closely you can see traces of pencil in the folds of the tent’s opening. Light and shade effects, however, were rarely indicated through pencil under-drawings. Sargent would leave that to the skill of his brush in mixing colors, giving his watercolors their fresh beauty.
(https://www.gardnermuseum.org/experience/collection/10882)