Most of the time Lightroom works really well. However there is one photo in my catalog (6000 photos) where Lightroom slows to a crawl. Whenever I move a slider it shows nothing until I release the slider and it takes a second to show. Other photos are very quick to show changes. What could be happening here?
What is special about this picture?
What kind of file is it?
How many pixels?
How many edits in the LR history pane?
What operating system are you using?
How much memory does your computer have?