2K Mastering

Short Overview

Many cameras today offer a recording resolution of 2048x1152 pixels (and more), however this is currently not an official delivery format for 2K. Permitted delivery formats for television and cinema can be summarised as follows:

HD Master : 1920x1080 pixels (16:9).
DCI "Cinemascope Cropped" : 2048x858 pixels (1: 2.39).
DCI "Flat Cropped" :1998x1080 pixels (1: 1.85).
DCI "Full Container" : 2048x1080 pixels (1: 1.89).

The vertical resolution of 2K images is 1080. The 2048x1152 pixels recording of (2K) produces an excess vertical resolution. This can be used for vertical reframing of the shot. The picture lock edit should be adjusted to the desired delivery format, and previewed in it’s entirety to ensure the crop is correct. It is important that the target resolution is made by trimming and not by a resize. The resize functions of the respective post-production software should be avoided, because they run the risk of damaging the image with aliasing artefacts.

When working with 2048x1152 rushes, the picture needs to be cropped by 72 lines (294 lines at DCI Cinemascope) for delivery. The surplus of resolution between 2048 x 1152 and 2048x 1080 is not sufficient to achieve a qualitative advantage to the oversampling, as the "resolution surplus" is only at 6% - 25%.

When shooting 4K (and higher), the difference in resolution is much larger, by a factor of 200% to 300%. 4K resizing is highly recommended to improve the image quality of the delivery format via a significantly higher recording format.

When delivering in the 2K format, be aware that no cinema projectors - even 2K displays - can display resolutions above 1080 vertical lines. Therefore any signal that is delivered and accepted anywhere will almost certainly be processed in order to rescale the output. It’s vital to ensure you control the viewers experience, so any deliverables above 1080 should be avoided.