Here is a brief explanation of the "process". I unfortunatley do not have a
significant "artist's statement". My purpose often is not any deeper than a desire
to exploit technology for the making of images that cause a viewer to say "How'd
they do that?" ... or to simply be amazed or moved into looking at images that they
would normally not have access to.
The material below is supplied to possibly be of assistance to the hosts of this
little collection. They should feel free to cut the text to whatever size or length
deemed approriate for their application. It can be cut down to a few paragraphs or
probably even down to 25 words or less! Cut, edit, slash and burn the bio as well!! :)
Have fun if at all possible!
and let me know if I can help some more
Andy
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here is a picture you can use:
http://www.rit.edu/~andpph/photofile-c/andy-1998.jpg
and here is a more "creative" one:
http://www.rit.edu/~andpph/photofile-b/andy-self-peri-5-2001.jpg
or this one:
http://www.rit.edu/~andpph/a-scanner/self-port-11-27-99v.jpg
========================================================
as for text materials -
Improvised Scanning Digital Camera
Andrew Davidhazy
Imaging and Photographic Technology Department
School of Photographic Arts and Sciences
Rochester Institute of Technology
http://www.rit.edu/~andpph
My interest in what is now popularly known as scanning photography started
when I was under pressure in graduate school to produce interesting
photographs of sports events. This was in the mid-1960's and I happened to
run across the photographs that George Silk had made of Olympic events with
a specially modified camera made for him by Marty Forscher. It was simply
talked about as a "photofinish camera" and a brief caption explained its
operation. It did not take me long to decipher the instructions, make my own
version and start making not only sports photos but exploring the whole wide
field of scanning photography. From photofinish to peripheral to linear and
then panoramic photography.
As digital cameras started to be introduced it did not take me long to
realize that the two approaches to image recording that existed with film
type cameras were being duplicated by digital systems. The 2-dimensional CCD
array cameras behaved like "snapshot" cameras, capturing the image of the
whole scene all at once. Large arrays were difficult to make and thus
expensive. Then manufacturers realized that they could achieve high quality
without having to make a large chip by the simple expedient of moving a CCD
array that was made up of a single row of sensors across the focal plane of
the camera. In this fashion they accumulated image information across the
field of view of the camera over time.
This is essentially how focal plane shutters expose the image in film-type
cameras. As we know, the process comes along with certain disadvantages
which I will not reiterate here. Certain other cameras exploit the
sequential exposure nature of the focal plane shutter but instead of keeping
the film still and moving the shutter slit, they keep the slit still and
move the film behind it. They make images of subjects by moving them in
front of the camera in some fashion, generally by rotating a subject or
rotating the camera while the moving film records the passing features of
the images moving over the slit.
These cameras are generically referred to in the technical literature as
strip cameras. The application of the system further refines the definition
as either linear or photofinish cameras, peripheral or rollout cameras or
rotating camera panoramic cameras. In each of these applications the film,
essentially, functions like "memory". And a very good memory at that!
As digital counterparts of the film cameras started to be come available I
soon saw the connection between the two systems and started to incorporate a
reference to the possibilities afforded by digital strip cameras in my
lectures and publications. Unfortunately getting my hands on a digital strip
camera would prove to be more difficult than expected as the price for such
cameras was beyond what I could afford. On top of it all, the manufacturers
did not see the potential of strip technology as being applicable to their
linear array camera designs and they made them strictly to serve the
advertising/commercial photography market.
My efforts finally were rewarded when I noticed that Kodak make a simple
print scanner whose function it was to pull a snapshot through it all the
while presumably looking and recording its surface. The price was $45. I
bought one on a hunch that it just might have the makings to help me
improvise a demonstration quality digital camera ... of the scanning type.
Before long the device was reduced to its basic components and soon
thereafter was doing things its designers probably never foresaw as
possibilities. Against the advice of colleagues who warned me that static
discharges and other disastrous effects would probably wreck the device if I
took it apart, I weighed the price of the device against the cost of a
dinner out and decided to go without one day and took the daring step of
disassembling the scanner.
All indications were that the scanner simply imaged the passing surface of
the snapshot it was scanning by simply passing it in front of a stationary
linear CCD array with the image of the print being reduced optically to
match the size of the sensor. Sure enough, at the end of a plastic funnel
serving as a light shield sat the CCD array. It did not take long to remove
it and install it in the back of a camera and soon after I was proving that
one could make rudimentary demonstration quality images that bore all the
earmarks of traditional film type strip cameras when used in similar
applications.
There were certain limitation to the Kodak scanner in terms of quality and
operation, the worst of these being the intermittent nature of the scanning
process that it was designed with. This posed no major problem when scanning
as intended but in my applications it was evident the scanner lost track of
the images thrown upon it by the camera lens every so often. The scanner
used these "dark" periods to transfer data to the computer. This left
somewhat disconcerting discontinuities in the final images.
I invested in another small scanner. This time it was a cheap hand operated
scanner. The kind that a person pulls slowly over some original material and
which during this process records the passing features of the image over
time. Just what one would expect of a scanning camera!
This particular scanner was a KYE HandyScan Color Deluxe hand driven rolling
scanner, although I have also seen an Artec version, and the cost was $10
during a promotion! In fact, the Artec was actually free at one time from
another source. I decided that the advantage of these scanners would be that
one would not have to stop during a scan sequence but that the scanner
software/hardware would work in combination to limit the rate at which the
scanner moved over the surface to one that the device could deal with in
uniterrupted fashion.
This proved to be the case and it was not long either before this scanner's
linear CCD array was installed in the back of a Minolta camera whose focal
plane I gouged out with a Dremel tool leaving flat surfaces on which the
printed circuit board of the scanner bearing the CCD array could be
attached.
The CCD array itself is normally connected to the rest of the scanner body
and hardware with a short 12-wire connector. I cut this wire in half, bared
each of the ends and carefully numbering each so as not to loose track of
the proper connections I made and extension cable to enable the CCD array to
be installed in the camera at a distance of about 4 to 5 feet from the
scanner body itself.
Unlike the approach with the Kodak array where I fixed the array in one
position,this time I chose to attach the array in the middle of a tongue
like device that could slide within a "C" channel glued to the camera body
allowing the CCD array to be moved across the focal plane of the camera. I
planned to slide the array from one side to the other by taking up a string
attached to one edge of the sliding tongue onto the shaft of a small
variable speed DC gearhead motor. This would allow me the capability of
"focal plane scanning".
To recap, then, the array itself functions as a "slit" shutter and the data
extraction process of the scanner is the memory or digital film. This is
reminiscent of my special interest in traditional photographic life: strip
cameras.
By way of further explanation it is important to mention that this scanner
device is designed to be moved over a surface. This causes a chopper wheel
to turn giving the scanner information about the rate of motion of the
scanner over an original. Since once the scanner is modified it is not
really practical to move the scanner body by hand, I first fitted a rubber
band over the shaft of the chopper wheel and with a variable speed DC
gearhead motor drove the wheen at a constant speed that was within the
limits that the scanner software could cope with. Later on I removed the
chopper wheel assembly completely and replaced it with an LED driven by a
variable frequency oscillator. This provided a steady signal to the
scanner's software that was not prone to be interrupted by broken rubber
bands!
A camera like this has many applications, From panoramic photography, where
the camera is rotated through an angle of 360 while it is gathering data,
line by line, until it has enough information to reproduce the whole scene
that surrounded it, a 360 degree wide angle photograph.
Cameras like this can, and in fact are, also be used to determine the order
of finish of cintestants in a horse race, a dog race or even a human race! I
decided to explore an application know ans "peripheral" photography.
This technique which is focused on recording of the complete outer surface
of (usually) cylindrical objects has been the specialty of a very few
photographers since was first considered, developed and applied in the late
19th century in archeological museums where Greek and other vases from
antiquity were photographed "in the round" to record the total outer
circumference of designs added to their surfaces.
Shell Oil Company developed a camera in the 1930's designed to photograph
pistons and cylinders to show areas of wear, etc. I started to experiment
with peripheral photography in the mid 1960's making peripheral portraits of
people. These portraits often did not look very much like the actual
persons!
For peripheral photography I placed the linear CCD array in the camera
roughly in the middle of the film gate.
Then, I stood on a turntable in front of the camera after having pressed the
"scan" command on the software controlling the scanner. The idea was that as
I rotated in front of the camera the lens would project continuously
changing features from my head onto the linear array located in the camera
image plane.
The scanner would be functioning as a "non contact" printing press where my
head would supply, over time, the changes in information that the scanning
array would then store in the computer's memory. I tried to make a couple of
turns or so during the time it took the scanner to believe it had scanned a
14 inch long print. Success!!
I also applied the camera to traditional peripheral photography by placing a
vase on a turntable and adjusting the image size and the rotation rate so
that a more or less acceptable reproduction of the surface features of the
vase was displayed in the final image. But the most fun was when I took this
camera to a science fair and made the opportunity available to visitors to
have their own "peripheral portrait" made. For the duration of the exhibit I
had visitors young and old standing in line to be photographed in this novel
way. Later on, as I reviewed the files from the event, I thought that some
were really intereting visual representations of what we call the real world
... distorted images perhaps but nevertheless fun to look at and ponder
about how the photographs were made and to enjoy the unusual "look" of these
images. I hope they bring a smile your way and hopefully they will also
spark your curiosity to find out more about the process or to devise your
own applications for it.
========================================================
brief bio ...
Professor Andrew Davidhazy received an AAS in Photographic Science in 1963 and
a BFA in Photographic Illustration in 1966 from the College of Graphic Arts and
Photography and an MFA in 1968 in Graphic Design from the College of Fine and
Applied Arts at the Rochester Institute of Technology.
He started his professional carreer in 1966 when he joined the Distillation
Research Laboratory headed by Dr. Kenneth C.D. Hickman as a Research
Photographer. Subsequently he was Director of the Director of Division of Arts
and Graphic Arts, College of Continuing Education, RIT from 1970-1979 and now
is a professor in the Imaging and Photographic Technology Department of the
School of Photographic Arts and Sciences at RIT.
He was the recipient of a 1988 Eisenhart Award for Outstanding Teaching at RIT
and the 1990 Professor Raymond C. Bowman Award from the Society for Imaging
Science and Technology. He was a NASA/ASEE Research Fellow in 1994 at NASA
Langley Research Center, VA. and the 1992 inaugural Kodak Visiting Professor to
Australia. He was a guest intructor at The Institute for Photography of the
University of Gothenberg in Sweden.
He has published and lectured widely on the general topic of "Simplified
approaches to Strip and Streak Photography and Scanning Photographic Systems",
as well as many other topics related to photographic instrumentation, as
invited speaker to conferences, workshops and seminars worldwide.
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