I've been recommending for years (both in my books and in the FAQS to the right of this forum) that you never use a photo larger than 1000x750 pixels in a video project. (For hi-def, you can go as large as 2000x1500.)
Using a larger photo does not make for better video. Video resolution is video resolution -- and putting a larger or higher definition photo into a project doesn't accomplish anything except slow rendering to a crawl and, more often than not, crash the program.
A 5 megapixel photo is about 1,664,000x1,248,000 -- or nearly 7 times our recommended size.
I agree with Steve.
In PrE, the Scaling algorithms in PS, or PSE, are better, and yield higher quality. This ARTICLE goes into more detail. Note: when originally written, the vast majority of video was SD, at 720 x 480 (NTSC), or 720 x 576 (PAL), but further down the article, mention is made of HD Projects, which run up to 1920 x 1080. That article also goes into detail on doing the Scaling in PS/PSE with automation.
Also, processing overly-large still images is very, very resource intensive, and it only takes a few very large images, before the computer and PrE will choke. This is even true with PrPro CS 5 and 5.5, which now have better Scaling algorithms, but can still suffer with many very large images. It takes a serious NLE workstation, that is perfectly tuned to handle them. If one really needs all those extra pixels, then I strongly recommend that they use After Effects, instead of PrPro, or PrE.
Thank you very much for your help.
Thank you for your help.