Thanks for the comments.
The best way of seeing it is:
(a) Calibrate your monitor against a stepped grey scale.
There is one on my web page
http://users.westconnect.com.au/~sjastro/small/
(b) Look at it in a darkened room.
(c) Reduce the size by 50% on your monitor.
What you should hopefully see is a circular glow slightly off centre to the right which takes up about 30% of the FOV.
Regards
Steven