Setting up the tripod
Creating panoramas
Capturing the images
Processing the photos
Publishing
Capturing the images for a 360x180 panorama part 1
In this series of web pages, I have documented the process which I currently use to create 360x180 degree panoramas. This page, and the next two, detail how to set up the equipment and capture the images. This page deals with the use of a tripod, next there is the setup of the camera and finally taking the photos.
Setting up the tripod.
Can you shoot hand-held?
My first panoramas were all shot hand-held and although it was possible to stitch them in Hugin, the amount of work required was enormous and most of the images suffered from parallax (see below). The only successful 360x180 degree panorama that I made hand-held was of Exeter College front quad, for which I also used the 18-55 mm kit lens on my camera. The sky and some of the grass were cloned into place, leaving some obvious anomalies in the picture, in addition to the more obvious over-exposure of the image. Click here or on the image to see it in Flickr or here to see it in a panoramic viewer (which uses Flash). Aldo Hoeben of fieldofview.com and moderator of the Equirectangular group on Flickr was helpful with his encouragement and comments on this image.
Parallax is the apparent movement of an object when the observer moves. So, when I turned on the spot, my camera moved in a circle and the relative position of objects in the photo changed. A failed early attempt at a 360x180 degree panorama is my picture of Lemon Quay in Truro on GigaPan, which failed partly because of the bollards, lamp posts and buildings that apparently moved by different amounts as I rotated on the spot. More distant objects are affected less by parallax than closer ones, a fact that enables astronomers to use parallax caused as the earth orbits the sun to calculate the distance to relatively close stars, take a look at the article in Wikipedia if you are interested.
Will a normal tripod do?
During the summer holidays, I successfully shot several 360x180 degree panoramas using a regular photographic / home video tripod and an Opteka 6.5 mm "fish eye" lens. This was a big improvement on my initial method, but still took a lot of effort to stitch, there were quite a few parallax errors and I have several unprocessed shots, because I got fed up with the effort needed to process them. An example of a completed panorama is this image from the Pink Granite Coast in Brittany, near Ploumanach, which can also be viewed in the immersive flash-based viewer.
Why use a panoramic tripod head?
These parallax problems led me to build a panoramic tripod head from a laser level kit with a metal turntable. I got the idea for this from www.360panoramas.co.uk, but my design is not the same, as my tripod head enables me to take photographs straight up and straight down (the zenith and nadir images), with the camera generally sitting in a portrait orientation. Using this tripod head, it is possible to rotate the camera around the nodal point (or entrance pupil) of the lens, eliminating parallax. I have been using this set-up from September to December 2012. At the start of December 2012, I bought a PanoMAXX tripod head and Hahnel Triad 40 Lite tripod, which I have been using since then.
My standard procedure is this:
- Level the tripod using the built-in bubble level, mainly by adjusting the length of the legs, but also using the fine-adjustment screws that you can see beneath the turntable.
- Attach the camera to the tripod head in portrait orientation and attach the head to the tripod.
- Rotate the turntable so the camera is pointing north and the scale on the turntable reads zero.
- Use the scale on the turntable to take six photographs at 60 degree intervals, then one straight up (the zenith) and one straight down, through the tripod (the nadir). This gives plenty of overlap for stitching and choice in the removal of some moving objects from the final panorama.
- Remove the tripod and retake another nadir shot hand-held. This enables me to remove the tripod from the final image using a photo editor.
My first trip out with the tripod head was a twenty minute visit to Carn Brea, which coincided with my daughter's piano lesson. I was able to walk from the car park and take the photographs for two panoramas near the Basset Monument on Carn Brea. It was possible to process the first of those panoramas that same evening. The reason it took a whole evening to process the images was partly because of the bright sunlight, casting strong shadows, which I cloned out in GIMP, because I had not worked out how to take and combine two nadir photographs at that point.
This page deals with the use of a tripod, next there is the setup of the camera and finally taking the photos.