Friday, December 08, 2006

Shooting Panoramas

Panorama Frames
Once you've collected your gear, it's time to shoot some panoramas.
  1. Pick a good location. This concept is basic to all photography, but is even more important when taking spherical images. I find you need to be in proximity to a tall object, or in a valley or canyon for the final image to be successful. You usually don't want 50% of your image to be sky. The camera should be about 1.5m from any object, including the ground.
  2. Attach your camera to your panorama rig with the lens' optical center at the center of rotation. This is something you should do before you venture into the field. If you are "just winging it", then make sure you are not closer than 3m to an object otherwise you may have too much parallax to correct in software.
  3. Level your rig. Use bubble levels to make sure your horizontal rotator is level and use a secondary bubble level on the camera to unsure your vertical rotator has the camera level. The first frame will be the "key" frame from which all angular measurements are made for subsequent frames. If this frame is not level, then the horizon in your panorama will appear as a sine wave, which can be corrected - but who needs that hassle?
  4. Set the camera to manual exposure and manual focus. If you are not shooting high-dynamic-range sequences, then expose for the brightest portion of the scene. Manually set you focus to the hyperfocal point for your lens/aperature. Attach a cable release.
  5. Shoot a horizontal series of frames with 50% overlap. My lens allows me to shoot a frame every 45° to achieve correct overlap.
  6. Shoot the zenith and nadir points. I shoot the nadir twice; first by pointing straight down to the top of the tripod, which is useful for stitching; second by hand holding the camera in the same approximate postion but with the tripod out of frame, which is useful for faking the nadir in the final spherical image. You should end up with a series of pictures similar to the photo on this page.

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