Crop vs Stitch Pano
Neil Morgan wrote:
Apart from the stitch issue, please don't look for it for this , see which one you think is stitch and which one is crop and see if it makes sense.
This is a projection issue. There's no perfect way of mapping an ultra-wide scene to 2D. Rectilinear (top) keeps straight lines straight, but expands the edges and turns circular things in the corners into ovals. What you get with stitching depends on the projection the program uses (which one is it?). "Best result" depends on image content and your personal preferences.
Some stitching programs support several different projections. The free Hugin panorama program for instance lets you convert to rectilinear, fisheye, stereographic (Samyang 8mm fisheye), cylindrical and a bunch of other projections (several variations of cylindrical). It may be used for either stitching sets or single images as input. It is rather clumsy to handle in the beginning though. It can use EXIF image data for quick tests, but it is able to build a PTlens-like lens correction profile for your lens if you provide a suitable set of images for a 3D pano.