Compare Renderings
Compare two renderings so that you can edit one image in reference to the other. The renderings must be of the same size and cannot have Relight enabled.
- 
                On the Rendering tab, click the Darkroom icon.
 - 
                Select two images for comparison:
                Important: The renderings must be of the same size and cannot have Relight enabled. The size is indicated at the top left corner, while Relight is indicated by a "R" in the top right corner of the image.
- Hold down Ctrl (Win) or Command (Mac) while clicking the images.
 - Click the Compare Images
                            
 icon.  
 - Optional: To see more of the Reference of Edit side, hold down Shift while dragging the image with the right mouse button.
 - 
                To view the display settings for the Reference image,
                    click the Show Information
                    
 icon.
             - Modify the Display Settings for the Edit image as desired.
 - 
                To export the Edit image without saving the display
                    settings, click the Save as
 icon.
             - To save the display settings, click the Save button.