The 200/250 added the "white balance shading" to the menu - I gather to help counteract chromatic abberation as it neutralizes color, and should be set up for each specific lens used per directions.
I followed the instructions using my new 17x fujinon. This require a subjective judgement of color at top at bottom your monitor while viewing a white source. The adjustment goes from -127 to +126.
It's subtle, but I ended up finding +10 gave me the most neutral color. Have others found this useful in correcting CA with the 16x? What type of settings did you use? How about with the coveted 13x? It might give a hint in comparing the lenses if the correction amounts are consistently different between these lenses.

Sean,

As I understand it, the white shading only corrects color bias and not CA, which is a result more of lens mechanics then electronics. Specifically lens dispersion.

The 200 comes pre-set for the Fuji 16x so I never even touched it yet.

Best.

Thanks Justin,
I since found more info here on the list:
http://dvinfo.net/conf/showthread.php?t=81636
Tim explains it as a a "form of CA". It is most certainly a correction for optics - using electronics...
Certainly, there are a number of complaints about the preset with the 16x from people there. The effect for me was quite subtle, and it was only after moving through the range several times that I settled on a spot different from default. Preset and 0 adjustment appear to be identical. Although the test is suggested at higher apertures, a lower aperture will make the adjustment easier.

This is part of the scene file with this camera, so keep that in mind when sharing scene files.

I guess what I was curious about, is whether this would help minimize the color fringing seen on high contrast details at open apertures that appear to be a common problem - casual tests don't seem to show any affect there. Generally, I'm quite happy with the lens performance I'm getting in my casual studio tests so far.

Can someone run me through the menu of the 200 in order to manually change the white balance as sometimes those two preset settings - A and B dont cut it.

Tyson,

Are you talking about something other than the manual white balance button on the front?

yes im talking about more than the A - B - PRESET setting button