picturematic

Panoramic Photography

Here is a run down of the equipment we are using for creating panoramic or "extreme wide-angle" photographs.

First, it is essential to have a way of moving the camera around the nodal point of the lens. The precise position of the nodal point, or entrance pupil, is what defines the perspective view. If this point moves as the camera rotates, the perspective of the scene changes, and the result is that the view of the same area of the picture will vary between different frames. You might think that mounting a camera on a tripod would allow the camera to be panned and tilted while keeping this constant, but the location of the tripod mount is more to do with the mechanical design of the camera, whereas the nodal point is a property of the lens.

For this reason a sturdy tripod, while necessary, is not sufficient. In addition you need a special tripod head that allows the camera to be positioned in the mount so that it rotates around the nodal point, both vertically and horizontally. For this reason we are using a special Manfrotto 303SPH panoramic head. This is an eloborate piece of metalwork that allows the camera to move around the nodal point, which is usually close to the front element of the lens. When set up correctly, the camera body will swing in an arc around the front of the lens.

The camera body is a Canon EOS digital SLR camera. It doesnņt need to be a particularly expensive one - we are currently using a fairly old EOS 350D which was one of the first of the "pro-sumer" DSLRs. In order to get a 360 degree panorama without an excessive number of frames we use a wide-angle lens such as the Canon 17-40mm L series lens, set at the wide 17mm setting. With the APS-C sensor of the 350D this is about equivalent to a 24mm wide-angle lens on a 35mm film camera.

With the lens set to 17mm and the camera orientated on its side, we can scan through 360 degrees in 12 frames. This gives enough overlap between each frame for the stitching software to be able to do its work later in the process. To give a full 360 degree horizontal by 180 degree vertical field of view we need to do two more scans above and below the horizon. The outer of these scans do not need to have quite as many frames, but it is more trouble to try to remember the correct number than just to keep it the same. Finally you need to take a shot pointing straight up (zenith) and one pointing straight down (nadir) to complete the sphere.

Having captured the images, they need to be post-processed using stitching software. This takes a number of overlapping images and by applying various correlation functions is able to reconstruct the entire scene. We use a program called AutoPano Pro because it automates a lot of the workflow in identifying and building the individual panoramas from a large group of photographs. There are quite a number of programs available for image stitching, some of them free.

The stitching process can be quite time-consuming. We use a server with eight cores and 8 Gb of memory because it is quite demanding of computing resources. Once the stitched image is created, it can be further edited as part of the conventional digital photography workflow. In addition it may be necessary to do some further editing work to remove artifacts such as tripod legs.

The Olympus OM System

I typically used two OM bodies, one carries a medium telephoto (135mm) and has 400 ASA film, the other has a 28mm wide-angle and has 100ASA film. I also carry a 50mm f1.8 lens and I intend to acquire a 2x converter. I think that covers most possibilities. Iņve got a 200mm f4 for telephoto work, but its a bit too bulky to carry around.

Ah, the OM system - its designer. The compact size, so popular in the seventies. Pretending to be David Bailey. The quality of the optics. The satisfactory "feel". The elegant simplicity of the OM2 which was some how lost with the later consumer cameras like the OM40.

http://www.olympus-global.com/en/corc/history/camera/om.cfm

http://en.wikipedia.org/wiki/Olympus_OM_system

Oh! damn, the two OM40s just got nicked. I left them in the office, out of sight. But they got taken, and I have an idea who might have done it but I canņt say anything, because it is only a guess. You have to be careful about accusations. Even if you are right there will be resentment. I also lost three Olympus Zuiko prime lenses. Plus some filters and stuff and the cases. Plus the partly exposed rolls in the cameras.

Cameras stolen - moved to Canon. Not quite the same - never seemed to match the 28mm wide-angle.