QTVR Tutorial
Volume Number: 12
Issue Number: 5
Column Tag: New Apple Technology
Panoramic Reality 
Getting started with QuickTime VR
By Andrew Nemeth
Note: Source code files accompanying article are located on MacTech CD-ROM orsource code disks.
Apple’s QuickTime VR technology is possibly one of the coolest things to happen to
digital imaging in the last five years. With it, you can produce and view 360-degree
panoramas of real or computer-generated scenes, without the need for expensive
panoramic cameras or any other fancy equipment usually associated with VR.
You create a panorama by photographing a scene with a standard 35mm camera
atop a tripod, taking twelve to eighteen photographs to capture a full 360-degree view.
Then, using Apple’s software, you “stitch” these images into a single PICT file, which
is then processed further to create the final, user-navigable movie, playable on both
Macintosh and WINTEL personal computers.
As there are already a number of general introductory articles on QuickTime VR
(see the references at the end of this article), the following will concentrate instead on
the tools and techniques used to create a photographic panorama.
Photographic Equipment
To keep costs down, and for the sake of portability, use of the following is suggested:
• 35mm SLR camera
• 24mm f2.8 lens
• (Lots of) 400 ISO low-contrast C41 negative film
• Sturdy tripod with built-in spirit levels
• Kaidan QP-1A QuickPan Panoramic Base
• Vertical camera mounting bracket
Note that some of the above is different to that recommended by Apple in their
QuickTime VR 1.0 Authoring Tools. The reasons for these differences will be noted
below.
35mm camera
I use two cameras for my work: a 25-year-old Nikon F (pictured in Figure 4)
and a more recent Nikon F90x. These are used depending on the locality, with the F90x
for general use and the older - indestructible - F reserved for more rugged activity.
Although not absolutely necessary, a 35mm SLR camera gives you the option of
using different focal length lenses on the same camera body, meaning you can use wider
lenses indoors and longer ones for outside work. They also tend to be better built and
feature more accurate focusing and metering. A 35mm camera also gives you a much
higher quality of image than the current crop of digital cameras.
As regards light meters, I prefer to use a hand-held model. Again, this is not
essential, but I find it to be more convenient than the built-in meters found in cameras
(especially the Nikon F, which does not have any kind of meter!).
24mm lens
As the first of many departures from Apple’s suggestions, a relatively
inexpensive Sigma f2.8 24mm lens is favoured for outdoors work rather than the
Apple-sanctioned Nikkor f3.5 15mm. Although the wider “Apple” lens does have
greater vertical and horizontal coverage (allowing for a reduction in the number of
individual photographs required in order to capture a scene), there are two major
problems with it: firstly, at a list price of US$2000 the 15mm is outrageously
expensive; and secondly, its field of view is too wide for outdoors work, with
everything more than 3 meters away looking as though it was on the edge of the
observable horizon.
Although other wide-angle lenses could be used (18, 20, 28, 35mm), the 24mm
is a good compromise on a cost/image-width basis. The down-side is that because
Apple has assumed everyone will be doing QuickTime VR with a 15mm lens,
adjustments have to be made to the MPW scripts which come with the Authoring Tools
in order to render the images properly (more on this further down).
400 ISO low-contrast film
A faster film gives you more scope to capture scenes whatever the prevailing
light. Although a slower film (50 or 100 ISO) is sharper and has less grain, for
QuickTime VR such advantages are lost during the software processing. Furthermore,
slower film is too slow to use indoors.
A low-contrast C41 film is recommended because it is the best kind of colour
film for capturing all the levels of brightness in a scene. A film like Fuji’s NPH 400
is sharp, fine-grained and - as it is designed for professional flash-lit photography -
more than capable of dealing with harsh outdoor light.
By the way, be warned that QuickTime VR chews through film - at 16 images per
panorama you can fit only two scenes onto a roll.
Figure 1. Tripod head with double spirit levels
Tripod and head
The sturdier the better. The one pictured (a Manfrotto, see Figure 1) is a 5kg
behemoth which features two built-in spirit levels to allow you to quickly level the
head prior to attaching the QuickTime VR-related brackets. In case you think you can
get away with using a lighter tripod, think again. You really do need a heavy-duty
tripod for this kind of work, because you don’t want it flapping around in the breeze or
moving suddenly in the middle of a sequence of shots. (Okay, I relent: for people with
bad backs and deep pockets, the Gitzo model 1228 tripod is a good carbon fibre
substitute.)
You also need the spirit levels, because the QuickTime VR software insists on the
camera being absolutely level when photographing a scene.
Camera mounting brackets
For the Authoring Tools to work, each 360° scene must be photographed by taking
a series of overlapping shots using a vertically oriented camera. To avoid parallax
errors when doing this, you must position the optical centre of the lens directly over
the axis of rotation (see Figure 4).
For an example of parallax error due to off-centre rotation, hold one finger 10
cm from your face, close one eye, focus onto the background, and then turn your head
slowly from side to side - notice how the background appears to shift from side to side
behind your hand? Now, keeping your head and hand still, turn your eyes from left to
right - this time the background doesn’t move relative to your finger! In the first case
your eyes are not centred on the axis of rotation, and hence the parallax error when
you turn your head. In the second example you are turning your eyes, the centres of
which do coincide with the turning axis!
The set-up I use is shown in Figures 2, 3 and 4. A quick-mount plate has been
added onto the Kaidan QP-1A Base (Figure 2) to make it easier to attach to the tripod
head. Black gaff-tape has also been stuck over the “deck” of the plate, as its highly
reflective silver finish caused lens-flare whenever the camera was rotated over it.
I prefer to use the QP-1A rather than Apple’s scheme of mounting a second tripod
head, because it is smaller, lighter, and you can set it to “click-stop” at the number of
shots you wish to take in a pan. (For the 24mm lens it has been set for 16 detents. It
can also be set for 8, 12, 14, or 18.)
Figure 2. Kaidan QP-1A Base with Manfrotto quickmount plate
The bracket used to mount the camera onto the QP-1A is something I made myself
from quarter-inch steel brackets, bolts and Araldite (Figure 3). This is a more
durable and much cheaper solution than Kaidan’s QPU-1 (US$180) bracket.
However, because it is not adjustable (unlike the QPU-1), separate brackets have had
to be made for each camera used.
Figure 3. Kaidan QP-1A base and (custom) 35mm bracket
The entire rig is compact, strong and very easy to assemble (Figure 4). Because
the vertical “home-brew” bracket has already been pre-aligned (when it was made),
the only calibration required when setting up on-site is the leveling of the tripod head.
Figure 4. Full QuickTime VR rig with camera and 24mm lens
Photographing The Scene
With the rig set up and the camera level, you will need to take a series of overlapping,
vertically-oriented photographs to cover a scene. The amount of overlap is in the
order of 30-50% and is needed by the stitching tool to help it align adjacent images
when it pieces together the final panorama. The more overlap the better, but too much
overlap equals wasted film and long stitching times.
Figuring out the amount of overlap (and thus how many photographs to take per
panorama) is very much an educated guess, with 16 shots for a 24mm lens appearing
to be adequate. Some people shoot 18, some live (very) dangerously and try to scrape
by with only 12.
There are a number of things to keep in mind when photographing a scene:
• Your camera rig must be (and remain) asolutely dead-level. The more out of
level you are, the harder it will be for the stitcher to piece the images together.