Creating panoramic and VR images is easier than it seems and you can use your standard camera, whether film or digital (although of course, if you decide to use a traditional film camera, you’ll need to scan your taken pictures to get them into your computer). Hopefully, after reading this and going out and taking a couple of photos, you’ll be able to identify what techniques and equipment will work best for you and allow you to get the most out of the various applications of panoramic and VR photography.
You’ll come across a vast and not always totally intelligible vocabulary when you start dealing with “panoramic”, “spherical”, “cubical”, “cylindrical”, “360°x180°”, “360°x360°” or “vr” photography. One way to try to clarify things is to divide between the basic types of final image the various terms listed above refer to. With a “VR object” image you want to circle around an object to see it from every perspective; with a “panoramic” image you want to show everything that is around you, or everything you can see from one single perspective.
In slightly more detail, a “VR Object” (or “object pano”) is either
- an item designed in a 3D program and then given a realistic surface by having photographs wrapped around / projected onto it
- an assembly of single photographs taken from different angles and/or elevations around a real world object, which can be assembled (or “stitched”) together using a variety of software in order to create an on-screen substitute for having the object in front of you and being able to move around to see it from all angles – what you get is not the real thing, but looks virtually like the real thing. The object itself (be it a toy car, a fire truck or the Golden Gate bridge) is at the centre of the full series of photographs, and the camera moves around it.
As long as the object is relatively small in size, the Manfrotto 300N Pan Rotation Unit (which is also a detachable part of all the other Manfrotto panoramic heads) can be used as a base on which to place the object. The advantage of using the 300N is that it allows you to spin your object through set angle steps, ensuring that you get a smooth, regular object VR at the end of the process.
The main focus of this introduction, however, is on panoramic photography, and we’ll concentrate on how to use standard film or digital cameras to create panoramic images. “Panoramic” normally means “wider than it is tall”, but often it doesn’t mean that the image covers a wider field of view than that encompassed by the angle of the lens in a single shot. Many APS & digital cameras have a panoramic setting that does nothing other than cut off the top and bottom of the frame, so the resulting photo looks longer than normal. What this of course also does is reduce the amount of the single frame that’s used to capture the scene, which reduces the quality of the final image. To use the full height and width of the film frame or CCD sensor, and get a panoramic image, you need to take several photos edge to edge with a small amount of overlap, and then “stitch” them together to get a single long image.
Contrary to object VR photography, in panoramic images it is the camera that remains at the centre of the series of images, and spins around the horizontal or vertical axis (or both) to take a series of photographs that capture a part or all of the surrounding environment. Basically, we can then subdivide between
- spinning on one axis only (normally the vertical axis, which creates a cylinder normally composed of a single row of photographs that covers front, back, left and right, but doesn’t take in the sky/ceiling directly above the camera or the ground/floor directly below) – all Manfrotto Panoramic Heads are suitable for single row panoramic photography. Models are:303, 303PLUS and 303SPH
- spinning around two axes (which creates a sphere composed of multiple rows of photographs covering the ground to the sky and everything in between: you are taking pictures from the center of the sphere and the landscape around you forms the inner surface of that sphere) – the Manfrotto 303SPH has been created specifically to facilitate multi-row spherical panoramic photography.
For these single images to fit together, you have to take all the pictures from the same point. If you move the camera even slightly, near and far objects will be subject to small (but important) distance shifts between one shot and the next (this is “parallax”) and the resulting images won’t fit together smoothly. (see these two images for a visual explanation of the parallax effect: vertical | horizontal)
So how you can spin the camera around without getting parallax effects?
By turning it around its nodal point. The nodal point is the exact spot within the camera/lens where all beams of light cross before hitting the film or CCD image sensor. By spinning the camera around this precise point, you can change the view without changing the position of the camera’s “eye” so near and far objects maintain the same relationship between each other between shots, and everything fits together more precisely during stitching.
Do you really need extra equipment?
While there are always ways of doing things by hand and with minimal equipment, a suitable tripod and head will help you to create panoramic images better and faster, both during shooting and in “post production”. The tripod itself helps in several ways: firstly, it makes the task of keeping the camera still and aligned much easier and quicker. Secondly, it allows you to set the camera horizontally level (which means, at the very least, that you won’t have to slant and cut each frame and waste precious space at the top and bottom of each shot when it comes to aligning and stitching the images). Thirdly, it will noticeably improve the quality and sharpness of your photographs, even when using fast shutter speeds. Fourthly, it holds your camera so you don’t have to!
In combination with a sturdy tripod, a Manfrotto panoramic head will then let you locate your camera’s nodal point so you can easily rotate around it (thanks to the adjustable sliding plates which also have millimetre position markings for future reference), and will help you spin your camera through set angles of rotation to ensure you’re not inadvertently missing parts of the scene in your photographs or wasting time/film/memory by overlapping your images too much (thanks to the click stop rotation base mechanism 300N which forms the heart of all the pano heads). All of which means you’ll avoid parallax errors between shots, and so you’ll spend less time hunched over the computer trying to stitch inaccurate images together, and more time out there taking great photos.
The following sections gives some pointers on getting from your newly purchased Manfrotto 303SPH pano head to your first full spherical panorama. Most of the basic information holds true for cylindical panoramas too. There are 6 major steps to follow:
- identifying and adjusting the camera nodal point above the pano head
- setting up your tripod for the pano shoot
- planning your shots (depends on camera & lens used)
- taking the horizontal rows of photos and the top “sky” photo
- taking the bottom “ground” photo of the sphere
- stitching pictures and generating the panorama
360×360 Panoramas Tutorial Part 1
i) nodal point adjustment
How to find the nodal point: To do this visually as we describe, you need to be using an SLR camera, if you use a rangefinder, TLR, etc, you’ll need to follow the same principle but comparing printed images… which is slightly more time consuming.
The objective of spinning the camera around the nodal point is to prevent near and far objects shifting (relative to each other) in your images during rotation of the camera for the shots that will make up your panorama.
The pictures to the left show the 303SPH head with its three sliding plates. In the case of an SLR with normal lens, the two green-coloured plates are used to get the centre of the camera lens barrel in line with the centre of rotation on the two axes of movement of the head. With your camera mounted on the 303SPH, look straight down the barrel of the lens, and move the bottom plate until the camera lens lies directly above the centre of the base rotation unit. Next adjust the plate that lets you get the camera lens in line with the centre of the handle on the side of the head that controls the camera’s tilt angle. The plate that’s coloured red in the picture adjusts how far forwards or backwards the camera is positioned; this is now the critical plate to move to identify the nodal point and position it correctly.
You need to slide the camera back and forth using the final plate, moving the nodal point (which lies on the lens axis you aligned as described above) until it is exactly located in the junction of the two rotation axes of the head. You can check this best by watching how a near and a far object shift in relation to each other in the view finder as you rotate the camera and head using the base rotation unit or the handle on the side of the head (compare with images vertical rotation and horizontal rotation ). You can compare on either vertical or horizontal rotation axes, but it’s safest to control the result in both directions. Keep adjusting the plate until there is no discernible shift between the near and far objects. Achieve this and you’ve successfully located the nodal point. If a very slight shift (in one or both directions) remains that no amount of subtle shifting of the red plate can get rid of, check the green plates positioning again; the lower one during rotation around the vertical axis, the upper one for the horizontal axis.
When the objects stops shifting you have found the right adjustment. You now can move the camera around both head axes without getting parallax effects. The more exactly you locate it, of course, the better your photographic results will be. After all that effort, it would certainly be a good idea to note down the position of each of the plates so that you don’t have to go through the same thing every time you take a panorama photo!
If you are using a single row head (303 or 303PLUS), you need to position the camera’s nodal point directly above the (vertical) rotation axis of the head, but the distance between the nodal point and the tripod’s shoulder has no importance. Again, look down the lens from the front and align the centre of the lens with the centre of the base rotation unit. Then use the second sliding plate to bring the camera’s nodal point along the lens axis (back and forth movement) into the head axis, again by looking at near and far shifting objects in the view finder.
360×360 Panoramas Tutorial Part 2
ii) setting up your tripod for the pano shoot
Once you’ve chosen your subject, you’ll need to find the best point of view for the panorama. Sometimes a centimetre to one side or another can make all the difference, so take a little time to make sure you’re happy with your location. Position your tripod (without the camera mounted) approximately where you want it and then, with your eyes as close to where the camera’s nodal point will be, look around in every direction (this will give you an fairly good idea of the end result). Adjust the tripod position and height to get the best view and then get the top plate as level as possible with the horizontal. If you don’t have a levelling accessory (such as a Manfrotto 338, 438 or 554, 555B or 556B Levelling Centre Column) on your tripod, you will need to adjust the tripod legs individually to level it. Depending on the software you intend to use to stitch together your pano image, it might be possible to correct wrongly-levelled images, but it’s much easier to do it correctly at this setup stage than at home on the computer. Levelling is very important for the final result – an incorrectly levelled panorama will look crooked.
iii) planning your shots
By “planning your shots” what we really mean is working out how many shots you need to take to get optimal coverage of the whole scene. Depending on the software you intend to use, you’ll need an overlap of about 30% between shots (in both vertical AND horizontal directions). During photographing dificult scenes with very less structure/detail, like white walls in large rooms, your software could have problems during stitching, because there’s less comparable information in the overlapping zones. In these cases, where possible and useful, it may be better to take more pictures with more overlap, but experience will help you decide.
Your software instruction manual should tell you how many pictures you’ll need based upon the focal length of the lens you’ll be using. As an example, with a focal length of 28mm (35mm SLR equivalent) you need 32 photos. This corresponds to one top photo straight up (+90°), 3 rows of 10 pictures each (one every 36°) at inclinations of +45°, 0° and -45° and one ground shot at -90°.
360×360 Panoramas Tutorial – Part 3
iv) taking the horizontal rows of photos and the top
Identify the correct exposure for your shots by measuring the brightest and the darkest regions and choosing a good average. You may decide to change exposure for some shots but you’ll need to do some tests, to find out how this will influence the final result.
Mount the camera and bring the head into the start position (which is usually the top photo at +90°). Take this shot, then bring the head/camera to the inclination for the first row (in our case +45°). Choose a horizontal start angle on the base of the pano head and remember it so that you know when you’ve completed the full 360° circle. Now take all your photos, row by row.
Finally, take a photo of the ground with the tripod in view – you might need it later.
Don’t move the tripod yet. Read on!
v) taking the bottom
Now take the camera off the tripod and hold it as close as possible to its mounted position, looking straight down at the ground. Trying very hard not to move the camera, move the tripod away and take the last photo. It’s important not to move and to maintain the correct angle to the ground. Make sure the camera strap doesn’t hang down into your picture and keep your feet as far out of the way as possible…
Yes, this is the hardest part. Don’t give up…
360×360 Panoramas Tutorial – Part 4
vi) stitching pictures and generating the panorama
If you’re using a film camera, you’ll of course need to scan your material first.
Once you have digitised all your pictures, you can manipulate them using your chosen stitching software.
- Remove lens distortion: your software may do this automatically for you; alternatively, use a bitmap image manipulation program (such as adobe photoshop, gimp, or any one of the numerous alternatives available at all price levels) or a dedicated software to do this. Correctly removing all trace of lens distortion is far from easy, but it’s worth the effort, and once you’ve found the right way, chances are you can use features of the software to automate part or all of the process in the future
Stitch the images together: this stage takes in everything from placing the images side by side, setting markers/placeholders on equal points in the overlapping sections of the photos; aligning the images and then fixing their position to avoid unwanted movement. If necessary, you can adjust brightness of individual images at this stage too to unify levels across the panorama. Before creating your final panorama, you have to level all the pictures, so that the resulting panorama rotates correctly around the sphere’s centre. This consists of telling the software where the ground should be. If you don’t do so, the final panorama will orbit crookedly.
- Generate the panorama: Now it’s time to create the panorama. Depending on the software used, choose the output format and projection method (e.g. QUICKTIME / cubical), set the size and/or resoulution and set the way the overlapping parts of your images are blended. Once the final panorama has been generated, check the result carefully. If you can’t see any edges, ghost images, or differences in brightness/contrast… perfect!
The above is a very generalised standard procedure for creating panoramas, but because this is only an introductory overview, you’ll need to find out for yourself which software is best for you, and how exactly to use it to its full potential.
Creating VR Objects
The only thing you need to do is mount the object you want to photograph on a turntable (the 300N rotator base included in every Manfrotto pano head can be used as a turntable and is well-suited to the task with it’s clickstop mechanism at variable angles).
Put your camera on a tripod to keep it at the same angle and distance from the object. Make sure that the object can be seen in its entirety in all positions. Rotate the object through fixed angles steps (e.g. 15°, 30°, 45°, 60° and so on – the smaller the angle steps are, the more fluid the movement will seem, but the bigger the filesize will be) and take a shot at every position, until you have completed a full 360° circle. Now all you need to do is use your software to assemble the single shots into the correct object Movie format (eg. QUICKTIME VR). That’s it.
It’s also possible to make more than one row of photos to show the object at various inclinations (normally from a high viewpoint and straight on from the side). To do this, you might choose to change the camera’s height, and/or to turn the object upside down (in which case, spin it in the other direction). Try to keep the objects centred on the turntable and the camera’s distance constant for all shots, or it will look as though the object moves or changes size in the final object VR.