This worked out pretty well for high quality 1080p 60fps video from the 4:3 3264x2448 JPG timelapse images,
cropping the top and bottom of the original images to 16:9 widescreen:

ffmpeg -framerate 60 -pattern_type glob -i '*/*.JPG' -vf crop=in_w:in_w*9/16,scale=1920:1080 -c:v libx264 -r 60 -pix_fmt yuv420p timelapse-60fps.mp4