Refine Calibration

the refine stage is where the majority of the "work" of a lens calibration is conducted on this page a user is able to modify every parameter of the existing calibration points while also being able to create completely new points to either improve interpolation between existing points or fill holes where points are missing at the end of this stage the lens graph should be complete and checked and the lens ready to use how to check a point start by moving to one of the calibration points, the fully wide, infinity point is typically the best one to begin with select the point in the graph view to display it's parameters pan the camera so that the centre of the calibration grid is positioned on the side of the frame observe closely for any drift in the position of the calibration grid, if drift is detected make adjustments to the parameters to bring it into line when happy with the calibration point, choose " confirm point confirm point " to save the changes and repeat the process for the other calibration points how to fill a hole if calibrating a non zoom lens, it's unlikely that any "holes" are present in the lens graph however, when working with a zoom calibration it's expected that there is a large part of the lens graph that is currently incomplete this is shown in red in the image below it's very important that lens information is populated for this area, otherwise, when the focus/zoom travels to this region then the interpolation is likely incorrect to fill the holes in, it is possible to manually add manually add calibration points in the refine stage this can be done by either using the chart or by manually entering the values move to a part of the lens that is not calibrated currently, it is recommended to try and match the structure of the lens graph and keep the calibration points in ordered rows and columns press " add calibration point at the current position add calibration point at the current position " to create a calibration point at the current position of the lens encoders press " april tag calibration april tag calibration " to calculate lens calibration information at this point, follow the same steps that are described in the earlier "primary calibration points" step alternatively manually adjust the calibration point without using the chart and purely using the calibration grid as a reference manually creating and adjusting points without the chart is a quick and efficient way to quickly complete a lens file, particularly when zoomed in as distortion is typically less present in these parts of the lens repeat this procedure until the lens graph is complete adding more calibration data depending on the lens you are calibrating it may be necessary to add more calibration points on either the zoom or focus use the calibration grid graphic to help identify areas where more data is required and add calibration points as needed