So I pulled the original data from MorphoSource.
Here is the rendering with a simple ramp from 15,000 to Max. You can see there are almost no staircase effects or moire patterns. This is with Normal quality, with surface smoothing enabled.
Unfortunately your VGStudio volume property didn’t work with this image, because original data was 16bit and along the way it got converted to 8 bit. The point is, all conversions (plus the segmentation) does impact the image quality. 8 bit representation is usually ok for dry skulls, but this appears to be wet tissue specimen (skin + soft tissue + bones). So if you need to use 8 bit representation, you will have to experiment with rescaleIntensity filter to preserve as much of the dynamic range associated with bones at the expense of soft tissue.
I do not have much more time today to comment on this, but we covered some of these discussion from 16 bit and 8 bit previously on the forum.
