Panoramic/Stitched Images

2. Using Equipment

Tripods, Monopods and Panoramic Heads.

Using a tripod or monopod upon which to rest the camera and pivot it around the lens nodal point seems a good idea, and pretty essential when the stitch involves several image rows or a wide panoramic view over 100º.  However, much depends on where the tripod mount is on your camera in relation to the lens, and the type of head that is fitted to your tripod or monopod.

Camera tripod mounts

Most DSLR's tripod mounts are situated directly inline with the lens axis, although usually well behind where the nodal point range will be situated.

Digicam tripod mounts are often located nowhere near the lens at all, which then makes life very difficult if not impossible. This Pentax Optio model isn't too bad, not in line with the lens maybe but nearer than many we have seen, including some where the mount is at the opposite end of the camera to the lens. This doesn't usually matter of course, but in this instance it does.

As we stated on the first page in reference to finding the lens nodal point, as the tripod mounts are usually situated well behind the nodal range, using these mount points with which to pivot the camera produces quite obvious parallax error, while pivoting anywhere under the lens seems not to. Well not in our experience anyway.

Monopods/Tripods

On the face of it a monopod seems a good cheap way of providing support, but there are a number of points to watch if using one. Besides having to pivot the camera around where the mount point is, which is no better than hand holding, and can be worse, there is the danger that relying on the monopod can lead to the camera ending up pointing upwards or downwards rather than staying level. The other problem is keeping it level as you then rotate it. 

And this is a basic requirement. If you are using a monopod or tripod to take a wide panorama, anywhere between 100° and 360°, it's pretty essential to have the camera rotate on the level. It's not enough to ensure the camera's level however,  the supporting device must also be level, in all aspects. Not just the head used, the base as well. Many tripods now have spirit levels built into their heads, but this doesn't actually help level the tripod, only ensure the camera platform is level, which is fine for a fixed view, but not much good for a rotatable one.

So in one sense a tripod is better to use than a monopod, in that the platform will be more stable and less likely to veer off the horizontal or vertical planes whilst being rotated, but no better in that the camera still rotates around the mount point and not the nodal point. An added problem is that some tripod head camera mounts aren't actually situated over the tripod pivot point but to one side. Therefore In some respects using a monopod or tripod can actually lead to a worse situation than hand holding. The only real benefit is that slower shutter speeds can be used with smaller aperture's and thus greater depth of field.

A secondary problem, as if this isn't enough, is that all of this only applies if you use the camera in the landscape position. You can't use either a monopod or a tripod if you want to use the portrait mode. Why not? Simple. Whatever head you have fitted, pan and tilt, ball, altering it's position to mount the camera in portrait orientation moves the camera and it's lens sideways, well away from the pivot point. It doesn't matter in normal use of course, but again here it does. The lens centre line is thus to one side of the line the nodal point should be situated on, and so if you rotate it like this it's a bit like being on a funfair ride, it goes in a circle around the pivot point. 

So all things considered using a tripod or monopod on their own isn't really of much benefit over hand holding, which is why we invariably hand hold for what we term 'compact panoramas', i.e. those under about 100°, even multiple row jobs.

Panoramic Heads

It's for the reasons outlined above that certain makers, Manfrotto, Novaflex and Kaidan amongst others, (we seem to discover new one's all the time), offer Panoramic/VR heads and other equipment to help the picture taking sequences for those who might like to invest in them. These are designed to help find the nodal point for the lens used, and to allow the camera to be rotated by a set number of degrees around their own base's fitted onto the tripod head, the tripod heads not being used for the rotation, the idea being that once levelled they will stay that way whatever the rotation.

As we said previously, finding the lens nodal point is a matter of moving the camera backwards and forwards until the correct point is found by observation. Two methods are normally used. Either the camera is moved along a slot which is used for the camera retention screw and clamped tight when in the correct position, which is crude but effective and quick. Or it's fitted on a base which is then moved. The second method usually involves movement via a screw thread, which is good for absolute precision, but slow. Additional methods are often used, depending on the design, so that once found, the nodal point for a particular lens focal length can easily be set again, without further re-setting. In one sense it helps if you use just one or two focal lengths, or one or two lenses, as it's easier and quicker to set up correctly. Prime/mono/single focal length lenses are better to use in that there is no chance of the focal length altering whilst setting or in use, as can happen with zooms. The amount of movement needed to move a zoom from a 24mm setting to a 28mm one is not much in actual terms, and you may not notice it when concentrating on other aspects of taking a shot, but it can have a serious impact if it is one of a number destined for a stitch.

There seems to be a considerable number of heads made, using various different designs. Two things that appear common are that all the heads are made in metal, and that none of this equipment is cheap, ranging from around £150 up to £400 and more. Here is a view of the head available from Novaflex. It costs at present around £240.

Novaflex Panoramic Tripod Head

It's a small neat design using dovetail slides to align the camera to the nodal point for the lens fitted, and a simple swivel base, there's no pre-determined click stop settings as Kaidan use. Anyone who is familiar with engineering will quickly spot that it is a variation on the basic design used in metal lathe compound cross slides, [these are the parts that the cutting tools are mounted on and movement is usually in two axis, some also swiveling to allowing taper turning]. Unlike some other makes the L-shaped camera bracket allows the camera to be used in either landscape or portrait mode, although there is no provision for multiple row shooting, and because of the design, none possible.

Kaidan make a range of different heads, some specific to certain digicams, but most are designed only for portrait use. If you look around on the web it appears to be the orientation setting most panoramic users prefer. It does give a deeper vertical view if taking just single row cylindrical panorama's, which is what it seems most do, but to our mind it's a bit restrictive. Another point is that most panoramic heads, whether they support both orientations or not, are primarily only designed to shoot single row panorama's. To take multiple rows extra equipment is needed. Considering the cost of these items we have to say we are not overly impressed.

Heads designed primarily for single row portrait use have arisen mainly because of the software used until recently. At first, Panoramic stitching was restricted to narrow single row use, so using the portrait position with a wide angle lens, many using fish-eye lenses where available, meant a 360° spherical QTVR could be assembled from just one circular row stitch. Now that the software has improved to the point that multi-row/multi-image stitches can be assembled this requirement is not so crucial, and narrower view lenses, cheaper to obtain and with less distortion, can be used instead. The problem is that in many cases the Panoramic head designs cannot be modified, and must therefore stay as they are.

As a result, some time ago we designed and built our own panoramic head. It's of fairly basic construction, using wood, but does what it was intended to do, help us take horizontal and vertical multiple row images through 360° should we choose. We have written a page on this  Panoramic Head  for those who might like to try this for themselves.

If you don't have the time, ability, or inclination to build your own head, but would like to try using one at the cheapest possible cost, then the Panosaurus head from Greg Rubottom  http://gregwired.com/Pano/Pano.htm  

is one to consider at currently just $75.95.   Made in plastic and metal it's a single arm portrait type design that can be used to take multiple images. A review of it can be found at  http://www.tawbaware.com/panosaurus_review.htm 

The next page deals with panoramic stitching software and stitching images.