(vincent van gogh - the plan)
(vincent van gogh - what remains of the canvas, which he destroyed)
(vincent van gogh - a later, calmer painting from near the same spot)
(vincent van gogh - the concept once again)
The AP has a story about a nice display at the Van Gogh museum.
Basically, from the above pictures you can see the way that Van Gogh planned his compositions carefully, even though as a (post) Impressionist, he painted somewhat spontaneously at the spot. It all went wrong when he had to take the canvas back to his studio to finish, and he ended up cutting out the couple and throwing away the rest.
"With the sketch blown up to scale, the "Loving Couple" would fit perfectly onto it, matching notations of the colors van Gogh intended to use, down to the word "jaune" — French for "yellow" — on the man's hat. The canal water is emerald green, as van Gogh planned, and the woman is draped in an orange shawl. Although the path is mostly brown, rather than pink, as the artist indicated, he began with pink and then later colored on top of it."-AP
Google has the best layout on this that I've seen.
The one problem is, the story doesn't really lay the images in question side by side, or at full resolution. So I've taken the liberty.
I wonder only slightly about the copyright issues here. After all, Van Gogh's paintings and letters are surely in the public domain (?!).
By the way, tonight is Museumnacht, or "Museum Night" in Amsterdam, when all the musuems are open until 2 a.m., and I'm planning to go out and take some photos, weather permitting.