I love the photos and the way you placed them.
Were you able to place a black screen or background cloth behind the flowers, or did you use photo software to cut them out & place on a black background?
Here is a couple of pano's I did of Tacoma last week. Consisted of nine photos stitch using Photoshop. Camera was Canon 5D with a Canon 70-200 lens. The resulting file was 225 MB's. These have been reduced of course.
Tacoma, Washington
Tacoma, Washington
Here are a couple more from PGR rides,
Dignity Memorial Vietnam Wall trailer
From a PGR ride
Dignity Memorial Vietnam Wall
Dignity Memorial Vietnam Wall trailer
I believe using a 50mm lens depends on the type of camera, a cropped or full frame. On a crop it might be fine.