Assuming you're using your photos to make an HD slide show, they need only be 1920x1080 pixels in size -- or no larger than 2500x1875, if you plan to pan and zoom over them. Using higher resolution photos won't give you better-looking slideshows. They only bog down the program and sometimes cause weird behavior.
Also, you don't say what your preferences are set to -- but look under Edit/Preferences/General. Is Default Scale to Frame Size checked?
When this option is checked, photos that you import into your project will be artificially resized to fit your video frame. (Although this may not work on some HUGE photos.)
When this option is uncheck, photos that you import into your project will appear at their actual size -- which may be larger than your video frame. This allows you extra pixels to create a pan and zoom.
omg!! Steve Grisetti replied to me!! i just want to thank you so much, out of this whole weekend i've watched more of your content than anyone, your voice and meter at which you talk is amazing. i've gotten more out of your tutorials than anything else i've researched on then internet. Also i subscibed to your muvipix youtube channel as well this weekend.
I'm actually doing a combination of pictures and hd videos....
you were correct, i did not have the "Default Scale to Frame Size" checked.. that fixed the issue even with the 6000x4000pixel pic that i shot. you are awesome and i cannot thank you enough...so many hours and you knew the solution in seconds, you're amazing!!