What are the best techniques to take 360° panoramas?

Question

I always wondered what are the best techniques, hints, and tips for a great panoramic shoot?

Answer 1

• Step 1 is to take the photos.

You need to keep the camera in the same location rotate it around what is known as the "no-parallax point". This will be different for different lens, and can also move when you zoom.

It is possible to purchase special tripod heads that allow you to rotate around this point rather than rotating from the base like a normal tripod would.

For large scale panoramas (outside, landscapes, etc.) the problems with parallax are reduced, but for indoors small scale shots the effects can become very pronounced.

Try to allow for plenty of overlap between the photos. If you aim for around 40%-50% overlap that leaves plenty of space for identifying common points.

• Step 2 is to compose the separate images.

For this I refer you to one of my questions - Recommendations for panorama creation/stitching tools

Further information: panoguide has some great in depth tutorials for all of the details of shooting and composing panoramic photos.

Answer 2

Here are the tips I've learned shooting 360°x180° equirectangular panos (full spherical view) for the past six or seven years.

The Manual Mantra

My mantra whenever I shoot a panorama is "manual manual manual".

Manual exposure will keep you from having exposure shifts between the member images of your pano set, due to autoexposure reevaluating each frame. If you are shooting a 360° cylindrical or 360°x180° equirectangular, it's highly likely you will get the sun in your shot, so meter both the brightest and darkest member shots, before setting exposure. Also consider whether bracketing for HDR/exposure fusing might be required. Pano shooters were the first people to use HDR techniques for this reason.

Manual focus will keep the focus point from shifting between member shots, due to autofocus resetting the focus. It's also good to remember to check your focus in liveview with 10x magnification--particularly if you're shooting 360°x180°s indoors with a fisheye, and you keep thinking as long as you're at f/8, you don't need to focus. You forget with close objects, you still do.

Manual white balance (i.e., NOT auto white balance). This is less critical if you shoot RAW, and can re-adjust the white balance on all the images in post, but if you're shooting JPEG is essential. Just as AE can adjust the exposure by re-evaluating the data in the frame, so can white balance make little color shifts.

Coverage

Consider the final composition. Before you even start clicking, visualize what your final image should look like. Just because you're shooting a pano doesn't mean you can ignore the rule of thirds or not look for foreground interest. Consider shooting multiple rows, not just turning the camera into portrait, for more vertical coverage. A pano doesn't have to be a thin horizontal strip. It can be any shape you want, if you shoot enough coverage.

Be sure you don't skip any images in the coverage. White holes in the middle of your pano are a bummer. Keep track of how many images you're using, and if shooting a grid of a large number of images with a longer lens for, say, gigapixel images, consider getting a precisely marked panohead that lets you keep track of your coverage.

Also consider that you may have to perform horizon correction, perspective correction, you may move the viewpoint (with 360°, you have full freedom to rotated any portion of the scene into the center of your pano), and you may need to rotate. Give yourself additional coverage for cropping.

Coverage applies to time as well as space. One of the most common errors you'll encounter when stitching panoramas are ghosts and clones from where a subject moved through the scene as you were taking images. Noting if you're inadvertently tracking something across the scene, and then simply waiting until they exit before taking your next member image, or taking multiple frames over time to make sure you have enough "clean plate" to erase the moving subject using masks and layers is a good technique both for panos and for HDR. Also consider using a tripod and a slow shutter speed or an ND filter to blur out moving subjects if there are a large number of them.

Overlap and Features

Make sure you have enough overlap so that your stitching software can find the hooks (control points) to connect one member image to another. A good rule of thumb is to overlap by around 1/3 of the frame. And if you're shooting multiple rows, that overlap applies both horizontally and vertically. Remember, that if you're shooting a 360° cylindrical, your first and last images must also overlap.

Be aware that featureless areas can cause issues with stitchers, and may require manual placement and control point definition. Not all software packages for stitching allow you to do these things, so if you have issues with this in the stitching process, look at other packages. Hugin is a good open-source package, PTGui is a good commercial one.

Leveling

Leveling is completely irrelevant if you're shooting 360°x180° spherical panoramas, because you have full cover and you can reset the viewpoint to anywhere in the sphere in post. But if you're not covering the full spherical view, and are making a cylindrical 360° or a less than 360° scene panorama, you need to watch that your camera remains level both in roll and in pitch. If you have a curved horizon when you stitch, the chances are very good you altered the pitch and/or the roll of the camera. A hotshoe spirit level can be useful for this if your camera has no leveling features, or only levels on one axis. Tripod spirit levels can be deceptive, especially with ballhead use, because they typically only tell you if the legs are level.

Luckily, horizon correction is very easy in most panorama packages. There's usually a preview mode, where you can correct for pitch by dragging vertically, correct for yaw by dragging horizontally, and correct for roll by right-dragging (or ctrl-dragging, if you're on OSX). If you're shooting 360°x180°s and got an S-shaped horizon, you just need to correct for roll.

Rotation and Movement Between Shots

Avoid shifting the placement of the camera between member shots. A little error, especially for distance landscape shots, can be tolerated in stitching programs, but most stitching packages assume you've rotated a stationary camera, and only a few can stitch together photos made from moving the camera itself.

Rotation of the camera should be done as close to the no-parallax point of the lens as possible. But again, it doesn't have to be exact if you're shooting distant landscapes. It's the closer your subjects get that the more critical parallax becomes. With typical landscape shooting, handheld can work, and you may even get by by simply rotating your camera around its tripod hole (assuming it's centered below your lens). I used to use my thumbtip in the tripod hole as a spindle.

Parallax

However. If you start shooting 360°x180° panoramas, or are shooting a panorama indoors, you will need to learn more sophisticated and precise techniques for rotating the lens around its NPP, both in pitch and in yaw. The easiest way to do this is with a specialized panorama head, such as a Nodal Ninja. But if you want to go handheld, then a plumbline or y-string (aka philopod) might be a technique to pursue.

John Houghton has a great article on finding the no-parallax point of your lens. It essentially requires having near and far subjects that can display precise alignment (i.e., have clearly defined vertical edges), and then seeing if you parallax shifts those edges closer or farther away from each other as the camera rotates, and then adjusting until you find the point where parallax has no discernible effect.

For more information on 360°x180°-specific techniques, such as nadir patching, see: How are virtual tour photos taken?

For more information on remapping panos, see:

• How to reproject and crop a 360°x180° panorama?
• How are "Little Planet" photos created?

Answer 3

• Do what you can to get equal-ish exposure of all the images. The software can't fix very obvious differences between two neighboring images, but on the other hand, there can (and will) be a lot of difference in the light around 360 deg.
• Hold your camera steady around the focal point in the lens. Some swear by special panorama heads to tripods, some do it by hand. (I'm mostly in the latter category, but I don't carry a tripod with me everywhere.)
• When in doubt, shoot it twice (if still in doubt, thrice). Vary your technique (i.e. practice).
• Practice with your software (See Recommendations for panorama ... tools)
• Practice the "whole stack"; taking proper care in taking the pictures can save you hours of work when stitching them - and vice versa.

I've experimented quite a bit (probably shot 100+ panoramas) by now, mostly by hand, and I still feel there's a large element of luck in my good ones.