Visible crew/equipment: After Luke cuts Vader's hand, there's a shot of the Emperor walking downstairs. The shadow of the crew is visible on the lower left corner of the image. It can't be the shadow of Luke.
Visible crew/equipment: When C-3PO And R2-D2 come up to Jabba's palace in the beginning of the movie, in the close-up, you see overhead stagelights in the reflection of C-3PO's head.
Visible crew/equipment: During the speederbike chase, there are several shots where the support arms holding up the fronts of the bikes are visible.
Visible crew/equipment: The rancor puppeteer's arm can be seen on the far right side of the screen as it starts poking at a hiding Luke. Widescreen version only.
Visible crew/equipment: During Luke's conversation with Ben's ghost, you can see a boom microphone in the background. This applies to the original wide-screen version.
Suggested correction: This was not a "mistake". The outlines showing around the beast's leg were due to the limited CGI technology at the time the film was made. With advances in special effects in the following decades, the filmmakers were able to enhance the CGI quality in later releases.
raywest ★
But it is a mistake to show that the Rancor is not real, and the outlines show that. It's certainly not intentional.
lionhead
Not sure what you mean that the rancor is not real. Of course it's not real. The issue is, at that time, it was not technically possible to show the beastie without the lines showing. I classify a mistake as something that was not intentional. In this case, it was, due to the limitations of CGI in the 1980s.
raywest ★