Ok – I see and I think you get my point. I like for picture “captions” to be in the WordPress “caption” field because I feel if I ever wanted to switch to a different theme one day… that theme’s photo viewer of choice just might use WordPress’ “caption” field for what to display for a picture’s caption. A picture’s title and its caption are two distinct things in my mind… kinda like I wouldn’t want to put a dollar amount in a description field in some accounting software.
Anyway, I wanted to mention one of my original reasons for wanting the change was invalid. I mentioned I needed the title to remain the same as the image file name… as when it was uploaded to WordPress. Well, it appears WordPress maintains the original name of the file separate from the “title” (in WordPress 3.5, the original file name displays in a box on the right when a picture is selected in the media library), so there was no merit with that reasoning.
So, I’ll be using the “put your picture captions for prettyPhoto in the WordPress ‘title’ field” workaround.