Glaring continuity error—costume disappears, impossible room logic, actor's position jumps between shots. Visible mistake, not intentional design. Kills immersion immediately.
If, during editing, you suddenly realize that the actor is holding the coffee cup in their right hand in Shot A and in their left hand two frames later in Shot B — that's a howler. It refers to those continuity errors that are so brutally obvious that even the most relaxed viewer is pulled out of the film. The difference from subtler jumps: a howler practically screams for attention. It's not the kind of mistake you forgive because the story is compelling — it's the kind that makes you laugh or curse.
On set, howlers often arise from sloppy continuity documentation or because hours or days pass between different takes. The actor is suddenly wearing a different shirt, even though the scene immediately follows in time. Or the spatial logic breaks down: a car is on the right side of the frame in the master shot, and on the left in the close-up. That's not subtle — that's a slap in the face to the viewer. In editing, you often only notice such mistakes when the footage is running on the monitor. By then, it's too late to reshoot.
Prevention lies in two areas: First, set photography — your script supervisor must take Polaroids of every setup, document set details, and prop positions. Second, editing control — always check match cuts during the rough cut, especially across cuts where continuity breaks. Some productions integrate continuity pages directly into the editing suite so you always have references while assembling.
A typical howler I experienced myself: a dinner scene where the protagonist sat in five different positions — once to the right of the table, once in the middle, once to the left. No edit could fix it without completely destroying the scene. The film had to be re-edited, and two days of post-production were lost. Howlers aren't just embarrassing — they cost time and money.