Almathera Ten Pack 3: CDPD 3/Almathera Ten on Ten - Disc 3: CDPD3.iso/scope/001-025/scopedisk3/digitize/digitize.doc

Text File | 1995-03-18 | 8KB | 121 lines

Digitizing with Digi-View by Ralph Reed.

I have been asked on several occasions to reveal my 'secrets' of
digitizing.  This file should answer all those requests at once.  It
will give you a good place to start with your digitizer.  As a
baseline, I use the NewTek Digi-View digitizer, with the Panasonic
WV-1410 monochrome camera.  A color camera can be used, but it only has
a third of the resolution of the monochrome camera.  Use a black and
white camera for best results.  I also spent the extra money to get the
camera lens with a variable aperature.  This gives better control over
lighting, contrast and focus.
     The first and most important 'secret' is lighting.  Ideally you
want the light to be exactly the same across the entire area you are
trying to digitize.  Practically, you get as close as possible.  I use
two lights spaced about three feet apart and at a 45 degree angle to
the center.  You need a light with a fairly wide parabolic reflector.
You want a wide beam, not a spot beam.  The position of the light
should be easily adjustable.  The lights I use come from Wal-Mart for
$9.95 each.  I also use soft white bulbs for a more diffuse light.  I
can't stress how important the lighting is to good results.  You can
NOT get good results without good lightling.
     The next thing to worry about is the camera setup.  You need some
way of holding the camera steady and perpendicular to the picture you
are trying to digitize.  You need a good camera stand of some sort.  It
is important that the camera does not move while you are digitizing.
You also need to get the signal from the camera to the digitizer.  Use
good, low noise cables.  Do NOT split the signal for the monitor.  I
use an old amber monochrome monitor for setting up the picture.  Its
nice and sharp and makes it easy to focus the picture.  I have a small
switchbox that allows me to send ALL of the signal to either the
digitizer or the monitor.
     The third element is the picture.  Some pictures just do not
digitize well.  I have about 50 meg of pictures at home.  All of them
are good, but only a few of them are GREAT.  So pick your pictures, if
you can.  Look for pictures that are bright, with good contrast.  Very
fine detail usually doesn't digitize well, especially in HAM mode.  In
HAM mode avoid fine detail horizontally.  Once you have the picture you
must decide what mode to use for digitizing.  For maximum resolution
use the hires black and white mode.  The color mode in hires is very
difficult to use because the color has to be just right to get any kind
of good results.  It usually works best if the picture is mostly one or
two shades of color.  The more color you try to use the worse the
picture gets.  For color use HAM mode.  There are two HAM modes,
320x200 and 320x400.  I usually use the 320x400 to get the maximum
resolution.  The 320x200 mode is fine if you are short on memory or
don't need the resolution.
     So finally we are ready to digitize a picture.  We have our
picture, the camera setup, and the lighting nice and even.  We need to
check the intensity of the light too.  You can have too little or too
much light.  If you have a variable aperature lens you can adjust the
lens to control the amount of light, otherwise you need to move the
lights closer or farther away.  If the picture looks washed out and
muddy you probably need more light.  Be careful though, too much light
can cause damage to the camera lens.  If you start to see after images
in the camera when you move the picture you have too much light.  DON'T
leave the camera starring at one spot for long periods of time, even if
the camera is off.  The vidicon tube can be damaged even if turned off.
Close down the aperature of the lens, cover the lens or turn off the
lights.
     Take a little time at this point to set up your picture properly.
Frame the picture in the camera.  Use the Digi-View camera options to
adjust the width or positioning.  Don't leave the edge of the picture
in the camera view.  A mass of solid color will throw off the color
calculations and a large, bright white area will shift the overall
contrast range of the picture and make it dull and muddy.  Try to make
the main subject as large as possible.  In HAM mode try to make the
finest detail run from top to bottom rather than side to side.  A
little effort here will pay off in the long run.  This is where you can
use your artistic ability to crop and frame the picture.
     The Digi-View software has many options, but with experience you
will have one baseline setup for most pictures.  Each picture will
usually be very close to the baseline setup.  With my setup my HAM
baseline is:
     Bri:4 Con:4 Sat:0 Red:8 Grn:0 Blue:-8 Sharp:4 This frequently give
me a perfect picture the first time.  I use the 4096+ option and 20
second scans.  This would probably be a good place to start, but will
vary with your setup.  Take a good picture and experiment.  Once you
have a good image record the setup.  There is no real substitute for
practice, but practice with a purpose and learn from what you do.
     Lets look at what some of the sliders do for your picture.  The
Bri controls the overall exposure, lighter or darker.  The Con on the
other hand controls the range of lightest to darkest.  If you increase
the CONtrast you make the dark areas darker and the light areas
lighter.  This tends to make the picture look sharper, but you loose
detail in the shadows and may wash out the bright areas.  To bring out
more detail in the shadows or in washed out areas lower the contrast.
The SATuration slider is usually kept on 0.  This makes all of the
colors brighter.  On some pictures it will brighten up the colors and
add sparkle to the picture, but usually it just adds little hot spots
of color and makes the picture look garish.
     The Red, Green and Blue sliders control the color.  This is the
tricky part if you have no experience with color.  The red slider
control Red and Cyan (a blue-green color).  More red increases red and
reduces cyan in the picture.  The Green slider control Green and
Magenta (a redish purple color).  The Blue slider controls Blue and
Yellow.  Reducing blue increases yellow.  The colors are additive.
Increasing one is the same as reducing the other two.  You can always
balance the RGB so that one of them is 0.  To adjust the color you need
to look at the picture and try to decide what color you have an excess
of.  If it appears too yellow, increase the blue.  Try to deliberately
overbalance the image with one color so you can see what that color
looks like and recognize it.  Like I said, this is the tricky part.
     The SHARPNESS slider controls the amount of dither in the picture.
Increasing the sharpness will make the picture appear sharper
(logical), but it will tend to increase the number of those little hot
spots.  I like about 3 or 4 for HAM pictures and 4 or 5 for hires
pictures.  On the other hand, lowering the sharpness will give you a
soft focus affect.
     Once you have a good image, save it to disk.  At this point you
are done in most cases.  If you have something special you might want
to go into Digi-Paint or Photon Paint and edit it a little.  Get rid of
any anoying hot spots, trim the border, sharpen up a little detail.
The touchup work can make the difference between a good picture and a
great picture.
     Thats basically it.  This should get you started, but you still
need practice.  If you found this useful let me know.  I'll be looking
for your work.

                              Ralph Reed
                              GEnie: R.REED