hese tests are the most extensive comparison ever published of laser
show scanners. We ran the tests as part of our technical research, and
then decided to share the results with our clients and the industry at
Over the two days of the tests,
we worked hard to be fair to every scanner:
Each scanner set was tuned, by Pangolin or the factory, to give
optimum performance before testing.
The tests were conducted at LSDI, with two non-Pangolin employees
present as "witnesses".
We photographed the results so you can draw your own conclusions
from the photos. (As described below, the original uncompressed photos
are available to anyone.)
We published our information for everyone to see. This is in
contrast to companies that may tell you about their test results . . .
but you have no chance to review their procedures, or use the same
test frames, or study photos of their results.
Of course, no testing
procedure can ever be perfect. That's why we suggest that ideally every
laserist or laser company should run their own side-by-side tests.
In conclusion, we feel these
tests are very fair, are very repeatable, and thus are very useful for
laserists. We welcome publication of procedures and photos from any others
who run similar tests. (Let us know and we'll add a link from this page to
your test data site.)
angolin's tests were conducted with the scanners on a breadboard, scanning
onto a test target 12 inches away. The test target is printed on paper
taped at the top and bottom to a metal plate. The paper is a bit wavy,
which can be seen in some of the photos where straight lines appear to
curve. The waviness does not affect the angle measurements.
Test setup showing projector with Pangolin TrueK 50 modifications
to Cambridge 6800 scanners
This setup is normally used by LSDI for
scanner tuning. As it turns out, the short, 12-inch throw made it hard to
photograph very small angles. If we re-ran the tests, we would use a much
longer throw, to enlarge the test patterns relative to the beam width.
he target is a sheet of graph paper pre-calibrated with angle markings
(not linear distance). Angle markings are absolute numbers, designed to
make it easy to read off angles when the scan is centered.
For example, in the photo below
the laser image stretches from about the 25 marking on the left, to the 25
marking on the right. This represents a 25 degree optical (peak-to-peak)
scan. It is not 50 degrees.
||hotographs were taken with a digital camera at a source resolution of 1536
x 1024 pixels. The photos have been edited to improve contrast, sharpen edges,
and reduce graininess for fast Web loading. Source photos can be around
300-400KB; after resizing and processing for the Web, JPEG versions of the
photos are about 10-20KB.
Despite the processing, the
content of the photos -- the actual appearance of the scanned images --
has not been altered.
The original, unedited photos
are available upon request from Pangolin. Please mail a Zip 100MB disk
with a stamped, self-addressed return envelope or a FedEx or UPS return
mailing label with return charged to your account. (If you do not provide
pre-paid return envelopes, labels and postage, we will keep the Zip disk
and use it for our own work!)
he Catweazle was tuned by Holo-Spectra.
The GSI G-120 and two CTI 6800s were tuned by Pangolin's William Benner.
The CTI 6210 was tuned by Cambridge.
Cambridge does not officially tune to, or promise
any particular ILDA tuning. Our understanding is that these 6210s were
factory-tuned to get the highest possible performance, which Cambridge has
previously stated is ILDA 60K to 66K.
In all photos, the laser
images for the three ILDA 30K-tuned scanners are being output at 30,000 points
per second. The TrueK 50 and 6210 images are being output at 50,000 points
per second, except for the 60K and 72K photos.
input gain on the Catweazle amp used in these tests was
"turned down" a bit. This meant that the maximum scan angle
available from our Pangolin software was about 25º. This could be fixed
by increasing the gain, but it was not ours so we did not want to touch it.
This affects the photos a bit; the Catweazle is at a
slightly smaller size than the other four scanners.
This page last updated:
Tuesday, June 19, 2007 08:54:20 PM