I'm normally a finger person, but do resort to my left thumb ( ! ) on certain occasions .....
Originally Posted by TPPhotog
It was once pointed out to me that with the standard issue 35mm SLR, because the lens axis is a couple of inches below the viewfinder axis, the camera-eye view is lower than the photographer's eye. However, turn the camera upside down and the reverse is true - it gives a higher viewpoint than would normally be the case, differing by twice the vertical distance between the viewfinder and the lens. This "periscope" effect by which, say, four inches can be gained can sometimes make all the difference when trying to photograph over a gate, fence, hedge, huge pile of money or whatever, but it does leave the shutter button best operated (IMHO) by ..... the left thumb!
Best wishes from the Cream County,