When I went out to take new photos for my background plate, I tried out the fish eye lens again to capture my HDR. This time I still took 4 images every 90 degrees around, but I also took one pointing straight up at the sky. I know that in theory, the fish eye should capture 180 degrees around including the sky straight up above. But since there was a significant amount of blank space at the top of my HDR from my first attempt over the weekend, I just wanted to see what happened when trying to stitch it together with a photo pointing straight above.
It turns out that the photo pointing straight up did fill in the missing space at the top. Now the same would have to be done for the bottom, but most of that would be filled with the tripod anyhow.
Since I am using the trial version of PTGui, it does not allow me to export a .hdr file. I thought I could get around this by stitching each exposure level together separately, exporting the JPG/TIFF image, and then bringing in those 7 stitched panoramas into Photoshop to create my HDR. But two problems arose when trying this out: 1) The two brightest exposure images could not be stitched in PTGui and prompted me to custom choose control points to help with the alignment but the image is so blown out it is hard to see anything at all. 2) When trying to merge the 7 (or in my case 5) images together in Photoshop, they are all slightly different coming out of PTGui and they don't align properly, giving this strange ghosting in a few spots.