Examples from the Web for viewfinder
Filming it through his own camera's viewfinder kept him steady: it was a necessary mediating tool.The ‘Hunted’ Gays of Putin’s Russia: Vicious Vigilantes and State Bigotry Close Up|Tim Teeman|October 6, 2014|DAILY BEAST
The viewfinder could be popped off so I could hold it low and compose a photo at waist level if the situation got bad.
He kept low and moved slow, keeping the viewfinder up so that he could keep the melee in shot.Makers|Cory Doctorow
"Not if you let me make it right away," Pete replied after a squint or two through the viewfinder.The Heritage of the Sioux|B.M. Bower
No, sir; I was just taking a picture of him, and the presidential party in the car come through my viewfinder and my camera.Warren Commission (7 of 26): Hearings Vol. VII (of 15)|The President's Commission on the Assassination of President Kennedy