Handheld panorama shooting

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Handheld Shooting Guidelines for Panoramas

You can easily get a good stitch with handheld panos if there aren't any important features close to the camera. Objects closer than about 30 feet are at the most risk of parallax error, where features move from shot to shot and no possible stitch can line everything up. Farther than that, and the effect is generally small enough to get a good stitch.

If you've shot a handheld panorama and you want a good stitch, choose control points that are far away. If you use autopano or another automatic control-point picker, look to see what control points it chose and delete the ones points that are in the foreground. Manually add some more control points in the distance if needed. Then you'll get a decent stitch without the optimizer trying to do the impossible. Those parts of the picture that are in the foreground might be doubled or won't line up, but in a field of grass or on a sandy beach that can be hard to spot.

When near and far objects don't line up during stitching, it's because of "parallax effect": the camera wasn't in exactly the same spot when the two pictures were taken, and this causes near and far things to "move" relative to each other.

The usual (wrong) way to shoot a panorama is to stand in one spot and rotate your body from shot to shot. When you do this, you are holding the camera in front of yourself a little bit and turning your body. This means the camera is moving in space, describing a circle around where you're standing. To get better results, instead of turning your body, turn the camera. Identify a spot on the ground, hold the camera over that spot, and shoot your first picture. Then for the next picture, rotate the camera while still holding it over that spot. As you shoot, you'll be doing a little dance where the camera stays in one place and you orbit around it. This will give a lot less parallax - the camera doesn't move so much between shots.

When referring to the camera being in "exactly the same spot," you should ask, "Which part of the camera has to be in the same spot?" That's a key concept for minimizing parallax and getting really good stitching with nearby objects. The camera should rotate around something called its "pivot point" - a kind of "optical center" of the camera and lens system. (Some people say "nodal point" but there is at least one paper online that disputes that terminology. So let's just call it "pivot point.")

If you rotate the camera around its pivot point, you won't get any parallax: near and far objects won't shift in relation to each other from one shot to the next. The pivot point is the spot that to be held in a fixed position in space - don't let it move up or down, left or right. Your goal is to find that point and keep it fixed in space as you rotate the camera around to shoot multiple shots.

A "panorama head" will do this. After determining the pivot point for your camera, you adjust the pano head appropriately and mount your camera in it. Then you put the pano head on your tripod. As you pan around in a circle, the pano head causes the camera to rotate around its pivot point. To shoot multiple rows, you have to tilt the camera up & down inside the pano head - the tripod's tilt system will not tilt the camera around the proper center of rotation.

For ultra-compact cameras, sometimes you can get away with something simpler. I built a little L-shaped bracket that would hold my camera sideways (in portrait orientation). I found I could mount the camera to the bracket and the bracket to a tripod, and the two rotation axes intersected very close to the pivot point. That is, I could tilt the camera up and down in the bracket and rotate the bracket around on the tripod head and get quite an acceptable full-sphere indoor pano.

The bigger the camera (that is, the longer the lens), the more you'll need a real panorama head. If you make your own bracket, be sure to align the tripod mount screw hole under the lens, which isn't always in the center of the camera body.

Also consider a "Philopod." A Philopod is a virtual monopod that helps you keep the camera over one spot on the ground as you shoot. It's just a string with a weight tied to the bottom. You tie the string to the lens at the proper pivot point, which is generally between the camera body and the front opening of the lens. (Actually, tying it anywhere on the lens barrel will probably be better than trying to shoot with no assistance at all!) It's a cheap and compact way to help you rotate the camera around its pivot point and also helps you avoid drifting up, down, left, or right between shots. With it, you can get good indoor panos or outdoor ones with nearby objects. Just a little assistance can be a big help - you usually don't need to be perfect to get a decent stitch. You'll find more about the Philopod and panorama photography generally at philohome, Philippe Hurbain's homepage.

The same PDF paper referenced above about nodal points describes a way to find the pivot point of a camera and lens system, regardless of what bracket or assistance you're using. Here's a quick version:

Find a place where you can see a nearby fence post maybe a yard or two away and a distant tree many yards away. Stand so the post lines up in front of the tree. Use your camera to frame the post-and-tree through the viewfinder so they're on the left side of the image. Now rotate the camera so you see them at the right side of the image. If the post still lines up with the tree, you've rotated around the camera's pivot point. If the post shifts left or right relative to the tree, you haven't found the right center of rotation. You need to adjust things and try again. (With the string trick, slide the string closer to the camera body or farther away. With other systems, do a similar in/out or left/right adjustment.)

For multi-row panos where you tilt the camera up and down, the string trick can still do an OK job. Your axis of tilting will be the knot just below the lens, not really inside the lens body where the pivot point is. But you might be close enough to get good stitches. After all, how often do you shoot a pano when there is a fence post just three feet away?

Don't obsess about the near field when the main points of interest are farther out. If you shoot a business complex from a parking lot in the center, the people looking at your pano might not care if the nearest cars look a little broken.

Other contributors to the Google group on Panorama tools wrote:

You may want to check out these do-it-yourself pano heads here and here and also what the author did for himself here.

 


This page was last edited April 26, 2008.