This isn’t totally on the conversion of the film, as theaters tend to forget to properly calibrate their projectors when switching from 2D to 3D.
When Avengers: Infinity War keeps its visuals in a colorful, brightly lit atmosphere, it’s a pretty crisp picture with minor dimming issues behind the glasses.
Even with that in mind, Avengers: Infinity War is dim enough to cause some eye strain over its roughly two and a half hour running time.
Unfortunately, there are wide swaths of this movie that venture into darker parts of the Marvel Cinematic Universe, and it’s in those moments that the third Avengers film manages to lose 3D points.