Mosaic Pano Help [Archive] - Nodal Ninja Forum

PDA

View Full Version : Mosaic Pano Help



jldt706
04-21-2008, 11:46 AM
I was shooting this weekend and ran into some issues when assembling the images. I am not sure why this is happening but my final image looks squished and distorted at the top. I realize there are some distortions to deal with when shooting a panoramic but I am trying to minimize this.

I was shooting a 17mm-85mm Canon lens 180 degrees in the horizontal 10 images, 4 rows in vertical (-30, 0, 30, 60 degrees) for a mosaic image of 40 images.

Any ideas on how to minimizes this? I was thinking to increase the amount of images shot by using a lens that is not as wide as 17mm, maybe a 50mm.

John Houghton
04-21-2008, 11:39 PM
When squeezing a very wide angle view onto a flat surface, there is inevitably some distortion. This is perfectly normal. Stitching programs usually offer a choice of output projections that will deal with the problem in different ways. Your image looks like an equirectangular format - commonly used for spherical images as it can accommodate full 360x180 degree views. You don't say which stitcher you are using. If it is Autostitch, then you are stuck with equirectangular format. Otherwise you can try alternative projections. Rectilinear (or Planar) corresponds to the format you get with a standard lens on a 35mm camera - what you could describe as a normal image. But as the angle of view increases, the image acquires a stretched appearance at the edges, becoming objectional at around 110 degrees. (The theoretical limit is 180 degrees, but the distortion becomes horrendous long before that). Clylindrical format can cope with 360 degree veiws horizontally, but is limited in the vertical direction similarly to rectilinear projection.

John