We are not able to accept images that exceed 100MB and/or 100MP. The megabyte (MB) upload limit refers to the file size, and the megapixel (MP) upload limit refers to the resolution of the image. Our upload limits are firm.
In order to make images able to upload, we recommend converting them to JPEG files. It is a more manageable file type to work with and will most often bring the file below 100MB.
If you are running into the megapixel upload limit, you will have to lower the resolution of your image slightly. This should not affect the print quality of your image. In our experience, anything over 150DPI at print size makes a nice, clear print in normal viewing for most images.