On Mon, 15 Jul 2013 18:58:40 -0700, Savageduck
wrote:

snip


Ok. Some successful experiments outdoors this afternoon using the 50
mm. lens and the Hoya R72 filter on the 5DIII.

A field of corn (maize):

http://www.flickr.com/photos/51646689@N00/9297836418/

A general view of the same vicinity. Not sure why such vignetting.
This is a 30 sec. exposure at 100 ISo and F1.8. At 10 seconds I still
get the vignetting but not as severe. But the vegetation certainly is
what I was expecting:

http://www.flickr.com/photos/5164668...ream/lightbox/

A crop of the above:

http://www.flickr.com/photos/5164668...ream/lightbox/

I'm much more satisfied now.

Much better.

Thanks! It's getting there.