A 7805 can cope with 35V input. Presumably you got 5V out with no load. If the camera expects to be able to draw 2A, (which seems a lot) then the solar panel isn't going to supply more than 200mA, so the output voltage will drop.
A 7805 can cope with 35V input. Presumably you got 5V out with no load. If the camera expects to be able to draw 2A, (which seems a lot) then the solar panel isn't going to supply more than 200mA, so the output voltage will drop.