As long as your closest subject is 3-4 feet (or more) away from the camera, entrance pupil misalignments cause few, if any, stitching problems - particularly when using very wide lenses. However, it becomes less critical the further away your subjects are from the lens. This alignment is important for the best quality results. Since the image is generated by the image sensor inside the camera, it is possible to use this quite effectively for entrance pupil alignment. Many digital cameras have a video output jack, or can display a live video image on their LCD screen.
#Nvr double pupil trial
If your camera is not a single lens reflex, or the viewfinder does not show exactly what the lens sees (as is the case with rangefinder, twin lens reflex, point and shoot, and most consumer digital cameras), then your entrance pupil alignment will probably have to be done by trial and error. Note however, that this only works if the camera has a reflex or through-the-lens viewfinder. Alignment of the panning axis with the entrance pupil of the lens can be achieved fairly precisely this way. This is done by mounting camera and lens on an adjustable VR pan head and observing the relationships of foreground and background subjects through the viewfinder as the camera is panned. Unfortunately, lens manufacturers do not mark entrance pupils on the lens barrels, so VR photographers need to determine this position before shooting. However, on wide angle lenses it is often found between the midpoint of the lens and the aperture ring. The position of this entrance pupil can be different for every lens. Otherwise, foreground and background subjects change their relative positions when the camera pans, causing misalignments and stitching errors between shots. Successful panoramic photography requires that the axis of the camera's rotation be positioned at the entrance pupil of the lens. The entrance pupil of a lens is the point about which a lens is rotated where close and distant subjects focused on the film plane maintain their relative positions to one another. Brian Caldwell for their advice and expertise All the principals of aligning a camera/lens combination properly for panoramic stitching still apply, no matter what term is used.
#Nvr double pupil series
However, for the panoramic photography done by most VR photographers where we stitch a series of sequentially panned images together, the proper term for this no-parallax point is the "entrance pupil." You will see it referred to both ways in different publications and web tutorials. For many years, the VR photo community mistakenly referred to the no-parallax point of a lens used for panoramic stitching as its "nodal point." In the case of certain swing lens design panoramic cameras, the rear nodal point is indeed the point about which the lens swings or pans.
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