Hi All,
I had lovingly crafted a wonderful post on this but my login timed out and it disappeared up it's own bum never to be seen again.
So instead of that imagine you have just spent 5-10 minutes reading an engaging and witty forum post packed with visual aids (which is what I feel like I've got after all that fruitless typing) and then go here:
http://www.nvscopes.com/ward-d-mini%20d ... ision.html
Cheers
Clive