suggestions for best photo file size for HD TV output

Would like to create a project with slides matched to music beats. Apprx. 5 minutes long. Anticipating many changes in photo location as I work.
Then will export to iDVD to create DVD for playback on HD TV.

What would the best suggested photo file size be for trouble free creation? Should I duplicate and decrease the files before the photos are put into FM?

I seem to be reading that the original larger files are not needed.
Can you give us some suggestions for file sizes and how best to pre-prep a project?

FotoMagico is able to use almost any file size. However, if you put in much to large images it shows a little exclamation mark on the slide in the storyboard. You can click on it and tell FotoMagico to reduce the file size for you automatically. Please keep in mind that FotoMagico is calculating the “scale down suggestion” on the current zoom-factors for this certain slide (if you zoomed in a lot you may not get presented the button). Because of that I would recommend the use this function only at the end of your slideshow design process. However, if you export the show as a movie file anyways you never need to downscale the images, because this won’t affect the exported movie file size in any way.

Thank you. The workflow suggestions are really helpful for me as a beginner.