Reason for not fixing
The Nuke team have decided not to fix this bug because...
Problem summary
Read node's format knob does not set/override the pixel aspect ratio for the image if the image has metadata containing the aspect ratio
Depending in the file format, this can be different metadata, for example:
TIFF: tiff/xresolution and tiff/yresolution
EXR: exr/pixelAspectRatio
DPX: input/pixel_aspect
MOV: input/pixel_aspect
JPG: hidden in Nuke, but it seems to use JFIF/XResolution and JFIF/YResolution
Customer reported version
nuke.13.2v3
Customer reported platform
rhel7
Steps to reproduce
1) Open Nuke
2) Read in any of the attached 4k1asp.{ext} files into Nuke
3) In the Read node, select the format knob>new, then create a new format called test, with a resolution of 3840x2160 and a pixel aspect of 2
4) View the Read node, the pixel aspect ratio should have changed, it didn't:
5) Read in any of the 4kNoMata{ext} files, and change the format knob to the test format, the pixel aspect does change:
Expected behaviour
For the image pixel aspect changed to change when you set it in the format knob
Actual behaviour
If the file has certain metadata, then the pixel aspect ratio can't be changed
Workaround
You could use a Reformat node, however that may introduce image degradation, as there would be an additional filter hit.
Reproduced by support
This bug has been reproduced in:
Nuke 13.2v3 - Windows 10, CentOS 7
Nuke 13.2v1 - Windows 10, CentOS 7 - *partial regression, for .tiff and .dpx files
Nuke 13.1v5 - Windows 10, CentOS 7 - though no longer effects .tiff and .dpx files
Nuke 9.0v1 - Windows 10, CentOS 7
Earliest version tested
Nuke 9.0v1 - his issue appears to be in all tested versions of the product for .exr, .jpg and .mov files
Other files may be affected, but have not been tested
