We had one heck of a good lightning storm last night:
Video extracts from 30 minutes of A7S video
Slide show using 12 frame captures from video
Don't beat me up on the image/video quality. I forgot to set manual focus and automatic focus wandered all over the place. These are the best segments...
There are four full sized frame captures following the video in the album.
I have some good news for you and other A7S owners!
It seems that you can get rid of the Amp Glow even at ISO 51200 if you use the Silent Shutter instead of the Mechanical Shutter. Look at the bottom of the page here http://3d-kraft.com/...Itemid=2#update.
Hope this helps you guys.
Can you test and confirm this finding when putting the A7S in long exposure mode?