The scene with R2-D2 in the canyon where he is captured by Jawas was one of those sequences shot-day-for-night, they turned up the brightness for those scenes in the early days of home video, the '93 DC LD was the first time they didn't. You can even see when it occur as it's done step by step in the wipes.
Other such scenes are the shot of the Sandcrawler just before "Look, sir. Droids.", in Empire you have the scenes with Luke seeing the apparition of Obi-Wan on Hoth, Luke's arrival on Dagobah and his later encounter with Yoda. These were often presented in broad daylight in the old video releases.