The idea
Flatbed scanners normally are used to scan documents, photos or film. The inventor of
the CCD flatbed scanner Ray Kurzweil
had in mind to develop a machine to scan paper and recognize the text written on it.
There are however more exciting applications for flatbed scanners. In this first
Photo-Vinc article information, is shared on how to use the scanner to make "photographs".
I will return to the term "photographs" in a moment but first lets see how I
realized that the dusty scanner left on my desk could be used for more exiting
subjects as intended by the inventor.
The reason why I started to use my flatbed scanner was that in the autumn of 2005, I
wanted to make some photographs of ful leaves. Normally I take pictures on
slide film but in this case I did not want to wait for the films to be
developed. I wanted to see the intensive colours directly on my screen and print
them on paper.
The leaves where put on the scanner and after a few experiments results where so good that
I started to make other experiments with three-dimensional objects on the scanner.
Is this photography?
Some people react strongly and say things like; "this has nothing to do with photography".
Emotional but interesting discussions sometimes follow.
I am not looking for general agreement on my statement but in my eyes this definitively is a
form of photography. It has to do with exposure, contrast, depth of field, and
even motion plays a role. Some people called it "scannography", I just prefer
to use the term photography and consider the scanner as a kind of slow camera,
which takes shots of single rows and assembles them together as a photograph. The
flatbed scanner only can be moved within some restrictions; instead of bringing the camera
to the subject the subject must be moved to the flatbed scanner.
Photography can be described as a process to capture and display an image. In the past this
was done with a lens, a shutter and film. The latent image was developed and
became visible as negative on film. Next step in that process was to
put the film an enlarger and a second lens was used to project the image on paper with a light sensitive coating.
Step by step parts of the original process have been replaced by other
technologies. In the case of using a scanner to take photographs the camera has
been replaced by the flatbed scanner. Another example is the inkjet printer which has replaced the
enlarger, this allows new possibilities and new limitations but it does not
harm the process description of photography.
At this point the time has come to stop with the argumentations. After all who cares,
how to call the technique described in the next chapters? It *is* fun,
creative and results can be stunning if the right technique is applied. I leave
it to the reader if this should be seen as photography.
What is needed?
To make photographs with a flatbed scanner a computer and a flatbed scanner are needed.
There is no special need to the operating system; results will be comparable on
all operating systems.
I started with an older Microtek scanner model, after a while I replaced it by a Canon CanoScan
4200F which had a higher resolution and allowed faster scanning. When putting
investment in relation with results it can be said that we are talking about
low-cost photography, what is needed is time and creativity. People who get
enthusiastic probably are going to spend more on the subjects (or objects, but
that is another philosophic discussion besides the question on the definition
of photography) than on the scanner technology itself.
The CanoScan 4200F scans up to 3200 dpi, this allows to enlarge the scans easily 10
times when printing at 300 dpi. This means that a 4-inch shrimp will grow to
a 40-inch sea monster. When currently have a scanner which scans at lower
resolution, don’t run to the PC shop. First look around for subjects to scan and
wait buying a better flatbed scanner.
Each scanner arrives with its own software. I tried the software that came with the
scanners I owned. This software does a fine job for scanning documents, OCR and
sometimes it offers creation of PDF documents. For this application of the flatbed scanner, it is
recommended to use a dedicated 3rd party scan Software package that
allows more flexibility in capturing the image and controlling the results. I
am using Hamrick VueScan
and did use Lasersoft Silverfast
in the past. Both applications will perfectly serve the needs to do the job. I
just stayed with VueScan because of the lower price and broader support for
various scanners. In the workflow, described bellow I will refer to VueScan
settings, of course the same things can be done with Silverfast or similar software.
Besides this there is needed cleaning material to clean the scanner before and after
scanning. An additional light source might be used but to start it is not
needed.
Which subjects to choose?
There are some limitations on the subjects to choose. First of all the main and most
obvious limitation is the size of the flatbed scanner used. The subject must
fit on the glass of the scanner scanner, which normally is the size of a sheet of letter/A4 paper.
Subjects do not need to be flat shapes like leaves; they can have three-dimensional forms
as well. Depending on the flatbed scanner, the limitation by Depth Of Field
(DOF) and available light it will be perfectly possible to capture an area up
to half an inch above the scanner glass.
Favorite subjects are all kinds of food, which allows variation. Consider not only how
the colours and detail will work but also think about making thin slices that
are almost transparent.
The good things about taking food, as subject is that in some extend there is control
over the subject. To get the variations or increase the character food as a subject can be cut,
squashed, dried or moistened (of course as long as the insider of the flatbed scanner stays dry).
Talking about taking care of the flatbed scanner: be careful with sharp and heavy
objects. The glass (or transparent plastic) is designed to carry paper and
books.
Try candies or flowers. When having the "scanner fever" visits to the supermarket are done
with complete different eyes.
Talking about fever, how long will it last? This probably depends on the supermarket
and the season of the year. Consider taking things from the street, sand or
stones.
DOF and available light
As said before, DOF typically is about half an inch. When subjects are more far
away from the glass they will not only be out of focus, the light emitted by the lamp
of the scanner also will be too weak. I did some tests to measure DOF in different
directions, scanning speeds and resolutions. During those experiments I could not find
that those parameters influence DOF. This means as much as that DOF variations are not
possible. Some flatbed scanners however can slightly vary the focusing point, this feature
however is foreseen for focusing to mounted slides and will not be a way for changing DOF.
Note:
Technique and workflow
Step 1: Preparation
Before placing the subject on the scanner consider how to pace it on or above the
glass. For three-dimensional objects clamps can be used. For flowers for
example a clamp as used for soldering electronics might be extremely useful. Be aware
that the clamp shown here has a very rough surface take care about the glass of the scanner.
Step 2: Selecting lighting and shadows on three-dimensional subjects (advanced technique)
There is needed a decision on the background to use. For a
perfect black background leave the scanner cover open and scan without light
sources like lamps or the monitor shining on the scanner. It does not have to
be completely dark in the room but the darker it is, the better the background
will get. Consider that the scanner lamp may shine on some objects around the
flatbed scanner, a ceiling with mirrors should be definitively avoided.
When a different background colour is needed it mostly can be changed later in with the
help of photo editing software. When the subject is light a black background
might be helpful to isolate the subject. When the subject is dark choose a
lightly background.
If a white background is needed there are 2 options. First of all a piece of white
paper or the cover of the flatbed scanner could be used as background. This may result in
shadows as shown in the next sample photograph where on the bottom of the leaf
there is a small but decent line of shadow.
To avoid shadows on the background a lighting source on top or above the subject
is the solution. A slide lightbox, which has a neutral colour temperature, can be used to create a
nice white background and even shows light though the subject when it is transparent.
Adding a filter can change colours. For this purpose lighting sheets can be bought from LEE Filters for this
purpose, those sheets are not cheap, consider to experiment with transparent
gift paper between the slide lightbox and the subject.
Be careful with to too intensive lighting sources. The picture bellow shows what happens
when the light is too intensive. In this case a photo lamp with fluorescent
tubes was used and the overexposure caused high interference, which makes it
impossible to take proper photographs. A sample of the effect is shown in the image bellow.
Another approach to get an interesting background from your flatbed scanner photo studio
is to use wallpapers, newspapers or dictionaries. As with subjects there are lots of
possible variations.
Step 3: Clean before scan
Typical and in special the somewhat untypical scanner use as described in this article,
leaves dust and fingerprints on the glass. This degrades the quality of the
scanned subjects. Read the scanner manual for instructions or follow these
directions to clean the scanner before start scanning the subject it later
saves time editing the picture.
The best way to keep a flatbed scanner clean is to use specialized optical-surface
cleaning fluid along with an anti-static cleaning cloth. I keep them around
because they are useful for a scanner and vital for a monitor (on which never a
glass cleaner should be applied).
A clean, soft, lint-free cloth along with a mild glass cleaner can be used as well.
Avoid paper towels they will leave dust on the glass. Do not use any type of
abrasive pad, cleanser, or alcohol-based product on the glass.
Do NOT spray the glass cleaner directly on the glass; this could damage the components
inside the flatbed scanner. Instead, spray a small amount on the cloth. Make sure the glass is
absolutely dry when finished this avoids streaks.
Be careful when the flatbed scanner is connected, electricity and fluids are not a good
combination. I therefore, strongly recommend to disconnect the flatbed scanner while
cleaning and ensure that no fluid entered the inside of the scanner before
connecting again.
Step 4: The scan
Before it is time "to press the shutter" in the scanner software there are a few
decisions to be made. Those decisions are reflected in the settings in the scanner
software. Instead of exposure time and aperture there are other technology
specific settings to deal with. The example here documents the settings for
VueScan 8.3.27. The VueScan software is updated frequently but basically
settings remain unchanged. There is no need to update each VueScan version,
check here
to see what are the last changes and decide if they are needed for the scanner in use.
With other software there can be found similar parameters needed to set. Therefore it is
recommended to read this even when another software is used.
Start VueScan and select "Default options" from the "File" menu (1) then press the
"Advanced" button (2).
There is the need to make advanced settings therefore select (3) "Advanced" in the 6
tabs for "Input", "Crop", "Filter", "colour", "Output" and "Prefs".
In the "Input" tab set "Bits per pixel" to 48 bit RGB (4) this will result in a 16 bit
scan. In the same tab the "Scan resolution" has to be set to the highest
resolution offered (5), when using a CanoScan 4200F this will be 3200 dpi. All
other options in the "Input" tab remain unchanged.
Next change to the "colour" tab, the "Crop" and "Filter" tab remain unchanged. In the
"colour" tab set "colour Balance" to "Neutral" (6) and "Output colour space" to
the colour space used in the photo editor software (7). I use Adobe RGB but this
might be different depending the settings in the photo editor software.
Consider the limitations of the sRGB colour space as provided by VueScan default
at the Cambridge in colour website.
In the "Output" tab deselect the checkbox "JPEG file" (8) and click on "TIFF File"
(9). The "TIFF file name" can be changed (10). The "+" in the filename will
enable automatic file numbering. The settings in the "Prefs" tab remain
unchanged.
Last settings before generating a preview are the settings in the "Prefs" tab where
the histogram is switched on by selecting "image" (11) from "Graph type" and
"Linear" (12) in the "Histogram type" selection box.
Now it is time to generate a prescan by pressing the "Preview" button. Nothing may happen
for a moment since VueScan requests the scanner to warm-up the lamp.
After the prescan has been made in the "Preview" tab adjust the crop box, then change to
the "colour" tab. To adjust the colours and exposure of the subject visible in
the preview window. Here first try to adjust "Black point" and "White Point"
(13) while observing the histogram. If it seems impossible to match the colour
try to modify the colour balance. Don’t worry to get it perfect. In the
picture editing software used later on, colour balance and histogram can be changed again.
Now it is time for the final scan and press the "Scan" button. This will take some more
time since the resolution and therefore the amount of data produced is higher. The picture
in the example above took about 45 seconds to complete on the CanoScan 4200F.
Avoid movements of the scanner and subject. I do live in an old house with wooden floors, when I
walk the table where the scanner is standing is shaking.
Step 5: Cleaning again
After seeing the result be patient, when a subject that might have caused dirt on the
flatbed scanner clean it first.
Step 6: Post processing in photo editing software
The final step is to load the image in Photoshop or another photo editing software and perform
the workflow used for editing conventional photographs. The photograph bellow
(which is not be best I made with my flatbed scanner) is the cropped result of
the subject used in this article.
Other sources of information
The technique described here is not unique; there are other people around doing
similar things. Katin Kamason
shows extraordinary flowers on her website. Have a look at the work of
Marschad Tudor who has been specialized on the use of a flatbed scanner as camera. Similar photographs by Ellen Hoverkamp. Lot of good work can be found on a special group in flickr.
Mike Golembewski
mounted a modified scanner on a large format camera. Results are different from what you get with the
technology described in this Photo-Vinc article, it is however worth to consider to use Mike's technique.
A similar but different approach by
Lieve Prins a female artist from Belgium
who is using a photocopier to create a special kind of Art.
It was said to me that the book "Start With a Scan" written by Janet Ashford and John Odam, (ISBN: 0201710978)
describes ideas and methods for scanning objects. I do not have the book, try to have a look
in it at the library or at the local bookshop before buying and verify if the contents match the subjects you are looking for.
Patri Feher a self-taught photoartist, teacher and amateur flower gardener, supplies more information in the form of an article.
Parti published details on how to scan your garden.
This article is less technical but gives good insight in how to use a flatbed scanner to take "photographs".
Scanner Magic offers a good overview on scanner magic.
Final words
In this article the basics of making photographs with a flatbed scanner have been
described. It leaves enough room for experiments and evolving an own technique.
When relevant the article might be enhanced by the comments send.
Some of my work is published in the "scannography" section
of the Photo-Vinc Blog. Besides this in the Food Gallery almost everything is made
with a flatbed scanner.
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