Lens Homing

overview this is a process that is required when using the following lens encoding options mk 2 external encoders mk 1 external encoders (legacy) mk 1 canon and fujinon smart boxes (legacy) preston interface box (legacy) it is conducted so that the ncam system can understand what the maximum encoder values from the lens are, and then to properly apply these to either the minimum or maximum end of the range process lens homing is a simple procedure that can be completed quickly, it should be conducted every time the ncam system is initialised or any time a lens is changed additionally, if using external encoders or a preston lcs then it must be repeated if there is any slippage in the motors/encoders webui when using the webui, lens homing is attempted when first connecting to the webui from a browser simply follow the onscreen instructions if the window is dismissed or the setup was not in a state to be homed, then the process can be repeated at any time by selecting " perform lens homing " from the actions tab full ui inside the full ui, lens homing is managed via the " devices " menu ensure the system is initialised and that the correct camera and lens is selected in the main camera details tab select " start homing " from the "devices > camera bar" dropdown this will put the system into a homing state, a notification will be displayed in the top menu bar and system status panel proceed to move the barrels of the lens to the limits of their motion several times while doing this, confirm in the system status tab, under the lens encoder section that values are being received and that they are either 0 or 1 when at the ends of the barrel once the lens barrels have moved to their limits several times, select "stop homing" from the "devices > camera bar" dropdown finally it is important to check that the encoder values are not inverted inside ncam reality the values from the encoders are normalised to a 0 1 range to ensure consistency it is necessary to make sure the 0 end of the range is mapped to the close focus/wide end of the lens and the 1 end to the infinity/tele end of the lens to do this move the lens to it's minimum focus and fully wide (if a zoom) and ensure that the values inside the first column of the "system status > lens encoder" section read 0 (or very close to) if any of the values read 1 then that barrel must be inverted this is done by selecting "invert zoom/focus/iris" from the "devices > camera bar" dropdown for example, if the lens is it at minimum focus but a value of 1 is seen in the system status, then the "invert focus" option must be selected the lens encoder section of the system status panel the first column indicates the "normalised" 0 1 range, the second column displays the absolute values that should correspond to the markings displayed on the barrel of the lens the absolute values are derived from the encoder mapping procedure, if a large discrepancy is observed between the reported and actual values, consider checking the encoder mapping of the lens metric focus values the focus values in the system status panel are displayed in metric, bear this in mind when comparing to values on the lens barrel