When you no know longer need a key exposure, you can remove it.
                                                             
                                                        
You can also remove key exposures of where the drawing is different than in the previous frame. When you remove a key exposure, the exposure of the drawing before it is extended over the exposure of the deleted key exposure.
                                                             
                                                        
 How to remove a key exposure
How to remove a key exposure
                                                            - In the Timeline view, select a key exposure to remove.
- Do one of the following:-  In the Timeline toolbar, click the Remove Key Exposure button. 
- Right-click and select Exposure > Remove Key Exposure.
 The key exposure is removed and replaced by the preceding exposure. 
-  In the Timeline toolbar, click the Remove Key Exposure