11-25-2011, 09:46 PM
I recommend you read this article published today by DPR. It is a synthesis of earlier articles he has written and research done in his lens rental company.
[url="http://www.dpreview.com/articles/7333489584/variation-facts-and-fallacies"]http://www.dpreview....s-and-fallacies[/url]
[url="http://www.dpreview.com/articles/7333489584/variation-facts-and-fallacies"]http://www.dpreview....s-and-fallacies[/url]