Photography on private land after signing contract ?

Yes, if your contract says no photography then why risk t?

Contracts aren't law, but the business can sue you.

A contract is not "a law", but it is legally binding. There would not be "criminal" charges for doing this, but you could be sued for "damages." The legal cost could run into the thousands of dollars.

They can prevent you from taking the pictures off their property. They can no this by (temporarily) taking the camera. They could remove the film (or wipe the memory) of the camera and then return it to you. However if they decide to sue you, they can hold the camera as "evidence" for the court case.

I am assuming that you want pictures of co-workers and friends. The smarter decision would be to set up a "going away" party and invite them to join you at a local favorite gathering spot and to take pictures of your friends there. The company can not prevent you from doin that.

Why invite trouble when there is an easy alternative?

Have someone else take pics. Just tell them what you want. They are not bound by a contract, that is law.

Contracts are law. There's an entire branch of the legal profession devoted to it - funnily enough, it's called "contract law".

Not sure why you'd risk being sued for breach of contract for such a trivial reason.