Thanks Tweeterland, Several were able to point out to me that Arthur Morris does photograph with a professional level camera, as well as being in places where there is lots of light, (such as the case he wrote about with the very sharp road runner photo). My conclusion is, for me at least, enjoy my 7D and the crop factor, and my 1.4 ext, and forget about the doubler.The one thing that Arthur did talk about in his ebook, about sloppy sharpness, or something along those lines, really hit me on the nose, as I have been shooting with out my tripod and my shutter remote, (whatever that thing is called, I forget, as I am over 50...).... I really appreciate all the help.Happy Birding to you all! And may your photos be tack sharp~~~

Vicki Biltz
Bonney Lake, Wa
vickibiltz at msn.com