# Glossary

Most Common Terms

Stiffness – The stiffness of a tripod defines how resistant the tripod is to motion when subjected to an external torque.  If the tripod is subjected to some $torque$, the angle that the tripod deviates is given by $angle = torque/stiffness$.  More stiffness means a proportional drop in the magnitude of vibrations.  Wikipedia

Damping – The damping of a tripod defines how fast vibrations die out.  More damping means a proportionally faster die out time.  The exact amount of time is dependent on the amount of rotational inertia on the tripod.

Pitch – Pitch is a twist or rotation about the horizontal axis that is perpendicular to the direction the camera is facing.  This is also known as the ‘Tilt’ direction.  A camera will see a pitch rotation as a shift in the image up or down. Wikipedia

Yaw – Yaw is a twist or rotation about the vertical axis.  This corresponds to pushing down on the top of a tripod and twisting.  This is also known as the ‘Pan’ direction.  The camera will see a yaw rotation as a shift in the image left or right. Wikipedia

All Terms

Fourier Transform – The Fourier transform

Rotational Inertia –  Rotational inertia, also known as angular mass, is the rotational equivalent of normal mass.  Rotational inertia has the same relationship with torque ($\tau = I\omega$) that mass has with force ($F = ma$).  Wikipedia

Torque – Torque is the rotational equivalent of force.  It is given by $\vec{F} \times \vec{r}$.  When we talk about stiffness on this site, we are always referring to the rotational form.  Thus, it is torque, and not force, that we are interested in.