I accidently discovered the fly mode one day and I've been using it since then to fine tune my camera position. I usually Drag, Grab and Rotate it the normal way first to get it close. Next, I switch to Camera View mode by pressing '0'. Then, press 'Shift-F' to switch to fly mode. The scroll when on your mouse will accelerate forwards and backwards, while moving the mouse simulates pitch and roll. I usually keep the camera selected as an object at the same time so if I get into trouble, I can press "ESC" to get out of fly mode then Grab,move and rotate the camera the regular way while still viewing from the camera (0).

Reddog9
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