Ncam Reality
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Rigging the Hardware
Lens Encoders

Arri LDS/LDA

6min

Overview

Ncam can read lens metadata that is embedded in the SDI signal of compatible cameras and lenses.

It means that focus, zoom and Iris information can be read directly from the camera. Lens calibration is still required however as no lens distortion information is provided via the LDS data

Required Parts

An LDS or LDA compatible Lens and camera body

Compatibility

See the section titled "differences in metadata" below for details on camera body compatibility

Instructions

Ensure LDS/LDA is correctly configured on the camera body, connect an SDI feed from the camera into the Ncam server

Ensure that the camera signal into the Ncam server does not have any metadata removed from it. If the signal is being looped through other devices then metadata can be stripped out of the signal

Inside the Ncam Reality preferences, ensure that the "Arri LDS Metadata" option is set to "Auto"

Importantly, the camera brand inside the Ncam Reality Main Camera Details tab must be called "Arri" for LDS to work

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Differences in Metadata

Unfortunately there is a discrepancy in how the LDS metadata is presented between different models of Arri cameras. This discrepancy impacts how a user of an Ncam system works with an LDS lens.

On the smaller camera models of the Arri range - Amira, Mini, Mini LF - a reduced payload of metadata is provided, this means when using LDS on these camera bodies, encoder mapping must be conducted.

On the Alexa LF, 65, SXT the additional metadata that is provided means that no lens mapping is required

Operating with LDS/LDA

One of the benefits of working with an LDS/LDA system is that Ncam is able to detect when the lens is changed.

When the system receives LDS data it will automatically try and select the correct lens from the Main Camera details tab. A pop up window in the Full UI will inform the user of this action. If the lens cannot be found in the database (it has not been calibrated before), then a popup will instead ask if a new entry for the lens should be created. This is an ease of use feature to save the user from manually entering the lens into the database

Parameters still required

It is still necessary to enter the details of the lens into the "Parameters" interface of the main camera details tab

Because of how the lens serial number is used as part of the LDS/LDA data, it is not possible to "override" the lens choice when using LDS data, the Ncam system will simply revert back to the lens that is being detected from the camera metadata