Using Ncam with Photographic Cameras

as a result of the huge increase in popularity of virtual production and it's surrounding technologies, the barrier to entry into the field has lowered dramatically one of the aspects this is seen the most is with the use of dslr and mirrorless cameras for acquiring footage the use of these types of cameras is possible with the ncam system, however there are some factors that are worth considering if intending to use this workflow ultimately, ncam would always recommended the use of professional video cameras, especially in live production environments hdmi output as an absolute minimum the camera must have an hdmi output, ideally this can be configured to provide a "clean" output additionally, it is helpful if the camera can generate and embed timecode on the hdmi output the hdmi signal must be converted to an sdi signal before it can be used in the ncam reality server converters such as this can be used for such purposes the signal into the ncam server must be no higher than 1080p in resolution delay when using camera's with only an hdmi output, there will nearly always be a greater delay present than using a camera with a live sdi output additionally it has been observed that the delay value needed to correctly align the camera image and tracking data can vary slightly when using hdmi to sdi converters, this can cause issues if trying to use this type of set up in a live production environment mounting the ncam equipment the use of a camera cage or other accessory system will help with adding additional rigging points to the camera body consider mounting the connection box or mk2 server on the camera tripod instead of directly to the camera body, investing in a longer usb c 3 1 cable can provide more options for positioning monitor mounts such as these can be used to place the camera bar in the hot shoe mount of the camera if using external encoders then the camera should be mounted to a baseplate with 15mm rods power the ncam equipment on the camera will require power, be aware that either an external power supply is used or a larger external battery with a d tap output lens encoding most photographic lenses have lens barrels that do not feature a hard stop, that is to say that the barrel of the lens can be rotated in either direction endlessly in a practical sense it is not possible to encode this type of lens reliably, instead, try and invest in a lens that has defined end stops the lens will also require the correct pitch of gearing on the lens barrel for the ncam external lens encoders to interface properly the external encoders support 0 5, 0 6 and 0 8 pitch gearing accessories like this can be used to add compatibility to a lens calculating sensor size as part of a lens calibration it is required to enter the size of the camera sensor that is being used on photographic cameras this can be hard to determine as typically only the overall size of the sensor is provided in the camera documentation and in most cases the sensor will be cropped when the camera is in a video mode to calculate the size of the actively used sensor an assumption is made that as much of the horizontal part of the sensor is used as possible, therefore it is only the vertical part of the sensor that needs to be determined and this can be inferred from the aspect ratio of the recording mode the following example highlights the process camera sensor size aps c camera documentation sensor size in mm 23 5 x 15 6 camera shooting mode 16x9 horizontal sensor size x (9/16) = vertical sensor size 23 5 x 0 5625 = 13 218mm therefore, in this example, the values for the sensor size that would be used in ncam are 23 5mm and 13 218mm image stabilization and auto focus lens or camera body image stabilization should be disabled stabilization can't be "tracked" via the ncam system and as a result, leaving it enabled will likely cause artifacts in the tracking auto focus should be disabled also, as the changes in focus do not cause the position of the lens barrel to move, so there is no way to encode the change in focus