Please ensure that the photo you take is not processed in any way. If you are taking the photo with your iPhone at default settings, it will be more than adequate. My iPhone is 6 years old and takes good enough pictures. I imagine iPads are no different.
Avoid taking pictures with inexpensive point and shoot cameras, unless you are sure about the quality. If a picture you take can be printed on a colour printer on 4 x 6 photo paper and show up sharp, it should be barely good enough, printing sharp on 8 x 10 however, is ideal as that gives us leeway to fix things like distortion.
Thanks, Rob Guetre