fishdoc

OK. I may have found the answer on another thread where a writer states: "180 degrees on a Nikon and 167 degrees on a Canon at 10mm" (for a fisheye). Could be that the different crop factor of the Canon sensor narrows the view enough that the shade is not a problem.

Any other canon shooters have experience with this set up?

I am shooting the 10-17 in the 5503 port on a canon 40D. I have tested this extensively and I am NOT seeing any cut-off with the standard dome shade. I even attached some clips to the edges of the shade so I could see where any vignetting was starting. Looks like there is still a few mm to spare before any shade would appear on the sides (of course much more margin at the top/bottom). I tested a variety of focal distances and f stops at 10, 17 and a few intermediate focal lenghts.

Any ideas why the standard dome port shade is not showing any vignetting in this configuration?

Thanks