hlg@cmu-cs-g.ARPA (Howard Gayle) (08/25/85)
The LEEP wide angle stereo photography system
a review by Howard Gayle
Microreview: expensive toy.
Minireview: a $1245 camera and viewer for extremely wide angle
stereo photography. It works, but there are bugs.
Mainframe review:
The elusive quality of realism has been pursued by many
photographers, even though photographic images differ from visual
reality in many ways. Two of the differences, flatness and
borders, are now under attack by Pop Optix Labs, a very small
company in the Boston area. Their LEEP (Large Expanse, Extra
Perspective) system is a stereo photography system with such a
wide angle of view that no borders are visible on the resulting
stereo images. The price of this extra realism is high, however,
both in dollars and in limitations of the system. In this review
I will describe my impressions of the system as shown to me on
12 August 1985 at the factory in Waltham, Massachusetts. In
addition to the usual disclaimers, I should state that I do not
own a LEEP system and have never put film through one. All the
specifications in this review come from the manufacturer and have
not been checked by me.
I have been using the term "LEEP system" here because the
camera and viewer are designed for use together. The key,
patented innovation of the system is that the camera and viewer
optics are matched. The camera lenses are NOT achromatic, but
are actually relatively simple two-element 39mm fixed focus
f/11 lenses. As a result, images on film exhibit marked barrel
distortion and severe color fringes. The three-element viewer
lenses are designed to compensate for this, and actually do to a
great extent. I detected slight barrel distortion near the edges
of some images, but this was only apparent when subjects with
strong vertical lines, such as buildings, were photographed.
The viewer is less successful in compensating for chromatic
aberration, and color fringes were clearly visible on dark linear
objects near the edges of the images. The main problem I had
with the viewer, though, was getting the whole image in focus.
Like a cardboard mounted slide projected with a flat-field lens,
it was possible to bring any single point to sharp focus, but
never the entire image. I should note here that I wear glasses
for myopia, with different corrections for each eye. I tried
viewing the images with and without glasses, and using both eyes
or only one. The most uniform focus was with glasses and using
only one eye, but even then the whole image could not be brought
into sharp focus. Another glasses-wearing photographer who was
with me reported similar problems with focus.
The LEEP camera is a strange mixture of low and high tech.
Designed to put 5 stereo pairs on a roll of 120 size film, it is
a large, black, surprisingly light ABS plastic box. The back is held
on by external clamps, and film is advanced by winding a knob. A
peephole shows the frame number from the paper behind the film.
There is no viewfinder, only a rough "gunsight" on top. There
is, however, a built-in level. The high tech side includes twin
magnetically released, quartz timed shutters with speeds from 128
seconds to 1/250s, plus aperture priority automation with a
silicon photodiode which integrates ambient light and flash. Despite
the 39mm lenses, the manufacturer does not recommend handheld
exposures slower than 1/125s. This plus the f/11 lenses makes
the LEEP a tripod-mounted camera for most shots. Controls are a
mysterious combination of thumbwheels, levers, and pull-out
switches, most unlabelled.
Manufacturer's specifications (unverified):
Shutters: twin quartz-controlled guillotine
Speeds: 128s to 1/250s in 1/2 stop increments, plus T
Flash synchronization: X up to 1/125s via miniature phone jack
Lenses: twin 39mm f/11 - f/45 Vistar Hyperchromatic coated lenses
Vertical angle of view: 45 degrees above horizon, 55 degrees below horizon
Horizontal angle of view: 140 degrees (90 degrees without moving head)
Focus: at f/11: about 2-4m, at f/32: about 1m to infinity
ISO range for aperture priority automation: 12-3200
Exposure compensation: plus or minus 2 stops in 2/3 stop increments
Exposure meter pattern: 60 degree conical
Remote shutter release: electric via RCA phono jack (!)
Self timer: 4, 8, or 16s
Battery: 9V transistor battery
Viewer: two separate viewers mounted on a single illuminator are standard
Viewer lenses: twin 39mm 3 element
Viewer interocular spacing: 64mm fixed
Mounts: 40 flexible plastic mounts are standard
Price: $1245 for about 3 month delivery, $1445 for about 2 weeks delivery
Front accessories: closeup lenses will be available
Film: 120 size roll film, usually fine grain color reversal would be used
Warranty: 90 days
Service: available from factory for fixed $50 fee
Mailing address: Pop Optix Labs, 16 Berwick Rd., Newton Centre, MA 02159
Telephone: 617-647-1395
Evaluation: The current LEEP system is a prototype which really should not
be for sale, except to very understanding users. I believe a
workable system could be developed in a few years, assuming
funding is available. Pop Optix is currently trying to find
funding without going to venture capitalists. As of my visit, 60
systems were on order (with $200 deposits) but only 3 systems had
been delivered. If the viewer can be improved, the images would
be truly spectacular, and I would even be willing to lug the
camera around, ugly as it is. Until then, this is a system for
stereo fanatics and rich toy collectors.
Plea: I put everything I know about the system into this review.
For more information, please contact Pop Optix, not me.
--
ARPA: Howard.Gayle@cmu-cs-g.arpa
UUCP: {seismo,decvax,allegra}!rochester!cmu-cs-pt!cmu-cs-g!hlg
USPS: Howard Gayle, CMU Computer Science Dept., Pittsburgh, PA 15213, U.S.A.