We will check on actual luggage restrictions for changes before our trip to GB and for changes in carry-on limits to and from.  My question is:  My camera will  not be in checked luggage since I do want a camera when we get there. : )  It will be carried on. I don't want to use a camera bag for this carry-on and the few other necessaties in the bag

Those with more experience than I have on such flights might recommend a sort of bag to use for carry-on?   We will get sizes to fit restrictions.