The varicam has an auto white shading alignment.
So a rough outline is as follows:
1) shoot either a DSC cam align chart or evenly lite solid white flat piece of paper.
It is very important that the chart or the white paper be evenly light and completely flat straight across. This requires the use of a HD waveform monitor to properly view that the chart is evenly exposed as well as if the auto white shading is correct.
The ability of an HD waveform to see this alignment is critical if you wish to fully understand what is going on not only for this alignment but many other creative and technical setups.
2) Refer to the specific varicam operations manual for gaining access to the auto white shading menu and the specific steps required.
Alternative option:
1) Seek the help and guidance of the engineering staff at a major rental facility you might deal with and ask them to set up the camera for you or hire a qualified DIT or video controller on your next job and see if they can do the alignment for you.
If you need additional info or more inside hints provide your email address and I will respond offline.
What lens were you using on the camera at the time you saw the possible “white shading” errors?
Tony Salgado