Originally Posted by mystery
I used to think this too, especially after reading Jason Turk's review but he later corrected this information to state that the Offset control adjusts the entire range.
I think that Greg Rogers stated it best in his review:
"The Memory1 and Memory2 Color Temperature modes include a
set of Red, Green, and Blue adjustments that affect the entire gray
scale range, instead of the usual sets of RGB gain and RGB bias
controls. Hence, those controls don't provide the ability to independently
adjust the low end of the gray scale, but the gray scale tracking
was more constant than most projectors that have those controls. In
addition, you can use the RS2's new Custom Gamma adjustments to
individually vary the RGB amplitudes over the entire gray scale range
to further optimize the gray scale tracking.
The Red, Green, and Blue Offset adjustments also affect color
temperature. Those adjustments again affect the entire gray scale
range, but they affect all of the Color Temperature modes (hence the
Offset terminology). It may appear confusing to have multiple sets of
controls, but the purpose of the Memory1 and Memory2 color temperature
modes is to allow the user to have additional color temperatures
for specific applications. The purpose of the Offset adjustments
is to recalibrate all five of the Color Temperature modes simultaneously,
which is useful during initial setup and when the spectral output
of the lamp shifts as it ages. Again, you can apply the Custom
Gamma adjustments to further optimize the gray scale tracking."
I tried myself to calibrate using the Memory1 Color Temp mode as Gains and the Offset control as Cuts but it was like a taffee pull or a tug of war because when I had 30IRE at 100% for R, G, and B and then I'd go and adjust 70% this would then skew the readings that I had previously adjusted for at 30%.