2 Replies Latest reply on Jan 24, 2014 6:20 AM by MikeKPhoto

    HowTo? Straighten bowed horizontal lines in uwa pano to be straight+slanted. PS Perspective Warp?

    ldallan Level 1

      I often use a 14mm uwa lens on a full frame for images like large grain elevators. When I have to get in close to the elevator, the panos end up bowed ("bulging")  and warped horizontally. I can get the vertical lines to be straight and vertical, but I have problems getting the horizontal lines like the roof and bottom to be a straight, and with slanted perspective.


      Here are some samples. First is a grain elevator where I’m able to get far enough away on a bridge to use one image, and a medium wide angle lens. It would be fine, except for power lines in front ... the bane of the urban panographer.



      The next is the same grain elevator where I am not far away at all. The pano is comprised on 7 images with the 14mm (360 degrees FOV), in portrait mode, using PTGui for stitching:



      The verticals are straight and vertical, but the roof line is bowed, and has a fish-eye appearance. I’d like to the get the roof-line to be straight and slanted in perspective with bottom of the elevator.


      I’ve used all the Projection choices in PTGui's Panorama Editor, but none seem to fix the bowed appearance. Cylindrical tends to be the least worst. I realize this is somewhat inherent with uwa panos.


      Is this something the new “Perspective Warp” in Photoshop CC is meant to address? If so, how?


      So far, I haven't had success in accomplishing getting better perspective with CC's Perspective Warp.