A phone photo can work — if the source is usable.
Choose the original image rather than a screenshot whenever possible. Avoid repeated compression, heavy filters and extreme digital zoom.
The player or subject should be easy to identify and not extremely small in the frame.
Avoid fully blown highlights or very dark areas with no recoverable detail.
Motion blur or missed focus reduces the detail available for printing.
If possible, use a version with extra space around faces, logos and jersey numbers.
The original camera image is usually a better starting point than a social-media screenshot.
