Looking back at some photos I took last night to test the IS out....mostly at 1/2 a second. The first batch of photos were garbage as I was carelessly putting a bit too much confidence in the IS. As I went along I started to more actively try to steady myself and control my breathing as I went along as was able to more consistently nail shots at 1/2 a second. There's definitely a technique involved and probably a learning curve, but handheld 1/2 and possibly even 1 second exposures are doable on this lens.
Quick example at 1/2 a second....nothing special, but very nice to see the beautiful star pattern in the specular highlights I've enjoyed on the 24-70II
Mystik610, I noticed you were shooting this lens on the A7R. I assume you are using a Metabones adapter. Aside from your great sharp results at slow shutter speeds, is there any way to know when the Image stabilization is active or not?
I turn it on and off on the lens (16-35/4), and I can't tell the difference. I've tried both green and advanced modes on the MB, and turned OSS on and off in the camera, and still can't tell if it is working when it should be. It seems to be working all the time, but I can't tell one way or the other.