Something off to the right caught his attention, and he quickly focused the binoculars in on it, tweaking the small focus knob to sharpen the image.
I remember my body making one brief, dizzying pitch forward and then, like the quick flip of a focus knob, a compensatory lurch back.
This is an indication that the focus knob needs to be rotated slightly anti-clockwise.
The Meade's binocular focus knob, for example, is on the underside, where it's difficult to reach.
His fingers found the focus knob, he twisted it quickly, and the image came into view.
Stuart twisted the focus knob again.
He adjusted the focus knobs and held the glasses as steady as possible against the quivering movement of the aircraft.
He squinted and adjusted the focus knob to clarify the ship's name on the bow.
She leaned forward, twisting the focus knob.
They also removed manual focus knob.