Degrees per Second to RPM

Multiply the rate by the exposure time to get the arc swept while the shutter is open, then work out what fraction of the frame that arc represents. Panning at 30 °/s with a 1/50 s exposure sweeps 0.6°; on a lens giving roughly 63° horizontally across 1 920 pixels, that is about 18 pixels of horizontal blur on anything with a hard edge. Push to 100 °/s with a 1/100 s shutter and the sweep is a full degree, around 30 pixels. Zooming in makes it dramatically worse, because a long lens covers only a few degrees across the whole frame, so the same angular rate turns into many times the pixel displacement. That is why a tight shot needs a far slower pan than a wide one to look equally smooth.

Because the two moves have opposite goals. A manual pan is the shot, so it has to stay watchable and controllable, which caps the rate at something a human hand can modulate. A preset transit is dead time between two shots, and the only thing that matters is arriving quickly and stopping exactly on the stored coordinates. The controller can therefore run a full acceleration ramp to whatever the mechanics allow and brake hard at the far end, using closed-loop position feedback that does not care what the picture looks like en route. Many domes deliberately blank or freeze the video during the transit for the same reason. When comparing products, the preset figure describes how responsive the system feels to a guard clicking a map, while the manual figure describes how it feels to shoot with.

Because almost nothing a camera head does is a revolution. Tilt is typically fenced into something like 200° of travel and often much less; pan may be continuous on a dome but is limited by cabling on many gimbals and on any yoke without a slip ring. Expressing a move as 0.083 revolutions per minute would be technically correct and practically useless. Degrees also line up with everything else in the workflow: field of view is in degrees, preset coordinates are in degrees, the site plan showing what each camera can see is drawn in degrees. Keeping the speed unit in the same currency as the angles means an operator can reason about coverage and timing without translating anything — until the conversation moves to motors and mechanics, at which point the revolution count is what the other side needs.

The usual working rule is to time the move rather than pick a speed: a pan that reads as composed generally takes several seconds to travel one frame width, and a slow reveal can take far longer. Convert that into a rate by dividing the lens's horizontal field of view by the seconds you want it to take. A wide lens covering 60° crossed over six seconds is 10 °/s; a 20° lens crossed over the same six seconds is only 3.3 °/s. Both feel similar on screen even though one number is triple the other, which is precisely why quoting a favourite speed without saying what lens it was for leads nowhere. Ease the start and the stop as well — a constant-rate move that begins and ends abruptly reads as mechanical no matter how well the middle is judged.

The stick sends a proportional command that the head interprets as a target rate, with full deflection mapped to the manual maximum. Almost nobody makes that mapping linear, because a linear stick gives a useless amount of speed in the first few millimetres of travel and makes fine framing impossible. Instead the curve is squared or cubed, so the first third of the stick covers only a small slice of the rate range and the last third opens up sharply. Two other settings sit on top: a dead band around centre stops a slightly worn stick from drifting the shot, and a zoom-proportional option scales the whole curve down as the lens goes long, so the same physical deflection produces a much slower pan when tight. If a head feels twitchy, that last setting is usually the one that has been left switched off.