You can find some occasional portraits -made as a test- here.
Yesterday I was in the equesterie next to where I live and -again as a test- I took some pictures at various high isos inside the stables, not really a lowlight situation but not at all "perfect light" neither...
Here is one of them:
The scene:
And a 35% crop of the image resized to 1024px longest side to fit on my forum:
The image was opened and postprocessed with Adobe photoshop Raw 6.7 Release Candidate
The cropped image at 35% was originally still 3829 x 2357 px
Iso 12800 is much better though, here underneath a sample image taken in the same stable, with crop.
And a crop as seen at 45% in Nikon CaptureNX, resampled to 1024 longest side to fit on this forum
Thanks for your attention and kindest regards,
Stany