1. Since Blu-Ray resolution is 1920x1080, does it make sense to reduce high resolution photos to 1440x1080 rather than the usually recommended 1000x750?
2. When reducing high resolution TIFF photos, does it make any difference to PrE9 whether I save as TIFF, JPEG, or PSD files?

Hi, AbWay. Welcome to the Muvipix community!

Yes, for hi-def video, it does make sense to use higher resolution photos. Maybe even as high as 2000x1500. Though, as you'd expect, it does take longer for the program to render files at that resolution. And it's probably a wise idea to work on a longer slideshow (say, over 3-5 minutes) in smaller segments so you don't overload the rendering cue.

As for which format you save it in, it really doesn't make much difference with photos. JPEG is a nice, compact format. You won't see much more detail if you use a PSD or TIF, so you might as well save yourself the storage space. (Unless, of course, you're using a layered PSD file or one that includes transparent areas, of course.)