Although this might come as common sense, some people might not realize that big file formats are actually bad for displaying on your digital photo frames.
Andrew, one of our blog search engin network bloggers, has a detailed explanation of which file formats are best for your digital photo frame:
If you do use an SLR, make sure to check out the file size of the photos, as SLRs often shoot rather large multiple-MB files that will take up most of you digital memory card if you don’t resize them. This can be done in almost any photo editor, and you should always trim your digital photos down to the standard 4×6 size if you want to get more of them on your frame.
Many frames also support TIFF anf GIF file formats. I recommend converting your TIFF and GIF files to JPEGS if at all possible You can do this with a photo editor like Photoshop, as well. TIFF files often lack any compression and this results in large file sizes. And with GIF, while they remain smaller, the file size is less recognized and may not play on all devices like JPGs will.
Overall, I recommend JPGs. You will be happier and so will your guests, who will get to see more photos on the same frame.