It is important to remember when placing photos onto a page in EDOnline that the resolution is determined by two things:

First, what are the pixel dimensions of that image? 

You can see the pixel dimensions of any image by clicking on it to view the details either in Manage Photos or by clicking on the + icon in the corner of the photo here:

This will create a larger window for this image with more details like this:

Since we print at 300 dots per inch (dpi) resolution, you can determine the maximum size that the selected image can be made on the page by dividing each of the pixel dimension numbers by 300. 

In this example, 3840 x 2160 pixels could be made as big as 12.8 inches by 7.2 inches and still be a minimum of 300 dpi. 

*Please note, that if the image is smaller than that, then the resolution will be higher, and that is perfectly fine. I will explain more about that below.

Second, what is the size of that the image on the page?

The image can be placed onto the page and it will be set at whatever size frame it is placed into, or if its not placed into a frame, it will be the default size. Either way, you can view the current resolution in dpi of that image at that size in the Photo Settings. It is the number below the thumbnail of the image in parentheses.

If the image is made bigger, that dpi resolution will be a lower number (because the pixels are bigger when the image size is increased). Conversely, if the image is made smaller, the opposite will happen and the dpi resolution will increase, see below:

The goal here is to maintain the image resolution is above 300 dpi on the page. You will get a preflight warning in EDOnline when you save the page if the resolution drops below 96 dpi, but in my opinion, that is already too low for an image to print clearly in a yearbook.

To answer the question at the top of this article, we can do some math to determine the size (in pixel dimensions) that an image needs to be at 300 dpi when made the size of a Full Page (8.5x11 inches). 8.5 inches x 300 dots per inch is 2550 and 11 inches x 300 dots per inch is 3300. 

This is less than 9 megapixels (or 9 million pixels) so any camera on a phone made after 2020 should be able to produce an image this size.