It's very tricky. It comes up easily in photos but visually....? I've never managed it.
Further reading and discussion that might be helpful to you in these past threads:
http://www.iceinspace.com.au/forum/s...ad.php?t=59562
http://www.iceinspace.com.au/forum/s...ad.php?t=69148
http://www.iceinspace.com.au/forum/s...ad.php?t=69937