Want to make a movie with jpeg sequences and need to know what to do to get smooth 24fps

Hey folks,

the title summarizes it pretty much what I am looking for. I shot a short movie and made jpeg sequences of it, to edit them via batchprocessing in photoshop, a HDR look.

now, I imported them to Sony Vegas Pro 11, set up 24fps etc, but the clip is slower than the original and I can't synchronize the jpegclip with the sound. I really don't know why and even if I try in options/preferences to change the time setup for the frames - it doesn't change anything.

What can I do, to have my jpeg as my original footage working in 24fps so that it flawlessly works with the original audio?

Thanks for taking time and your help,

Best
Marc