"photography is both an art and a science" is this a contradiction?

explain what your answer means for how we understand the photograph's status as knowledge.

It is not a contradiction, but a paradox, much the same as knowledge. The paradox lies in the fact that it is both. Science in the fact that it is technical when you are first learning. How to use the camera, the right lighting, what lens for what effect, etc. Art in the sense that even after you have mastered the science, it is that elusive gift or talent that makes one person a good photographer & another great. Knowledge is the same. Knowledge is the learning, the facts. Wisdom is the application that exceeds the sum total of the knowledge.
Blessings!

No contradiction. The workings of the camera are science, the positioning and perspective is art.

Like architecture, the buildings are built using science, but when looked at after can be considered art.

It is not contradiction; it is merely attempting to "illuminate" two different aspects of the same thing. We can see these two by simply looking at the term "photo-graphy."

The aspect of "photo-" denotes the idea of photons and light. This element of the activity is the scientific.

The aspect of "-graphy" denotes the idea of writing. Much like handwriting is distinct to individuals and, as such, artistic in a way. This element denotes the artistic.

Putting the two together, we "write with light" which is a blending of science as well as art.