Fast Lens in a Dark Place

I did some more experimentation with my Canon 50mm 1.8 in dimly lit indoors locations, mainly since I haven't had time to do any other photography lately!  My office gets really dark at night with only a couple of overhead bulbs behind a frosted glass fixture.  I did some shots in there a while back, but I hadn't yet really pushed the lens to its limits.  So, I set my aperture to 1.8 and cranked the ISO up to 1600, where I was able to get shutter speeds up to around 1/100 or a little  higher.  The resulting pictures are rather grainy, which is to be expected at a high ISO.  However, it's still possible to get usable shots.  Chloe is always curious when I'm playing with the camera gear and I took this picture that managed to capture her big soulful eyes.  Considering the light, or lack there of, I'm happy to get a shot like this.  Having a wide aperture can make all the difference in getting the shot in poor lighting.

Shutter: 1/160 (handheld)
Aperture: 1.8
ISO: 1600
No flash