(c)1996 William Beaty
These holograms aren't extremely hard to
produce, so don't be put off by the massive
amount of discussion below. I'm just trying to
cover all bases.
1. HOW DOES IT WORK? WHAT'S THE THEORY?
2. I DON'T UNDERSTAND HOW TO MAKE THEM.
3. I TRIED IT AND IT DIDN'T WORK!
4. HOW CAN I VIEW THESE HOLOGRAMS INDOORS?
5. WHY DOES THE PLASTIC HAVE TO BE BLACK?
6. CAN'T THESE HOLOGRAMS BE VIEWED IN "TRANSMISSION" MODE?
7. HOW DID YOU MAKE THAT CUBE IN 3D?
8. WHAT'S THE BEST PLASTIC?
9. THIS IS *NOT* HOLOGRAPHY!
10. ARE YOU INSANE?!
11. THIS IS A HOAX, RIGHT?
Q: I DON'T UNDERSTAND HOW TO MAKE THEM!
A: Follow the instructions on the top page, but also take a look at the
1. Make curved scratches as shown above
Your first hologram should be something very simple. How about the letter
First draw the little "V" as a guide. Draw it near the bottom edge of
your piece of plastic. Next, use the dividers to make lots of curved
scratches above the "V". For each scratch, place the point on a different
spot on the "V." Each scratch should be a quarter-arc or even a
half-circle. Don't change the distance between the metal points.
Make about twenty scratches. Even more is better.
2. Make LOTS more scratches on the plastic plate
Each scratch will create a single glowing dot in the finished hologram.
That means you should make lots and lots of curved scratches. If you just
few scratches, your hologram will look like a collection of sparks. If
you make enough scratches (spaced closely like the grooves of a vinyl
record album), the rows of sparks in the hologram will start to look like
glowing white lines.
IMPORTANT NOTE: Each scratch must look dark and shiny. If they
dusty, then your hologram won't work. If the sharp point of the compass
makes a squeeking noise, then that scratch is useless. Make your
scratches slowly, so the compass point doesn't squeek.
3. Cut the little picture off the bottom of the plate
The scratches ARE the hologram. If you wish, you can cut your
little "V" drawing off the bottom of the plastic plate. If people only
see the plastic plate with "sandpaper marks", they won't know what the
picture looks like until they see the actual holographic image.
Q: I TRIED IT AND IT DIDN'T WORK!"
A: If your hologram doesn't work, the problem could be from three main
sources: the illumination, the viewing angle, or the hologram itself.
A) ILLUMINATION PROBLEMS
Holograms are sometimes hard to view, so at the start, USE SUNLIGHT
OUTDOORS. The bright light will make your holographic image easy
to recognize. If sunlight is lacking, then use an overhead street
light outdoors at night. The dark background and the small bright
light source gives good results. Once you know that your holograms
are working and you can see them under sunlight, you can try bare
lightbulbs indoors. Even flourescent tubes will work somewhat if you
stand so the tube is lined up perpendicular to the hologram. But
avoid light bulbs and flourescent tubes at the start, they make the
hologram too hard to see.
B) PROBLEMS WITH VIEWING ANGLE
When illuminating holograms indoors, avoid using a bulb in a fixture
that has a white reflector, or one that is very close to the white
ceiling. These will make the hologram image blurry. The ideal
light source will look like an intense pinpoint having a black
background. A small clear lightbulb hanging from a wire in a
darkened room is best. If your only lamp has some sort of reflector,
you might consider painting the reflector black. A frosted bulb will
work OK if it is about 5 ft or more from your hologram. A transparent
light bulb is preferred. Halogen pin-spots (used in track lighting)
work very well.
These holograms work best when the reflected background is dark,
so try shading the windows and turning off all room lights except the
one used for illumination, or try viewing them at night. This
isn't a requirement. However, a dark environment makes the holograms
appear to be VERY bright.
Stand so you are facing the light source, or with the light source
directly overhead. (If the light source is behind you, your hologram
will only operate over a very small range of viewing angles, and the
correct angle might be hard to find.)
C) FAULTY HOLOGRAM
Hold the hologram so the scratches are humped upwards in the center.
If you hold it so the scratches are bowl-shaped (humped downwards)
then the image will be upside down, and the depth will be inside-out!
While looking at the scratches, tilt the top edge of the hologram
slowly farther away from you and slowly back again until you start
seeing bright highlights in the scratches. Try tilting the hologram
until you see the reflection of the light source in the plastic
surface, then tilt it back again so the light source image appears
to move up a few inches above the scratches. You should see a
collection of highlights in the scratches. These highlights ARE the
If you still cannot produce a hologram, then as a last resort, try
drawing a single circular scratch on plastic like so:
| . |
Hold this scratch in the sun, and you should see two little highlight
reflections which move around along the scratch. The highlights
will be on opposite sides of the circle, like so:
/ \ little highlight reflections.
| . |
These little reflections ARE THE HOLOGRAMS. They are holograms of
a single dot. When you make a complete hologram plate, every single
scratch should have a little highlight when you hold the plastic
plate in the sun. The little dots of highlight-reflections form
the hologram (of the letter V, for example.)
If you don't see these little moving reflections, then there is
something wrong with the scratch. You may have pressed too hard
with the compass point, or swept the point along too fast and
produced a white scratch with a shredded internal surface. Or
your compass may be too wobbly, since the scratched line must
be very straight and smooth. If it has little wiggles, it won't
produce holographic images.
Use a sturdy, expensive compass. I tried the $2 kind, and it didn't
work. It wobbled and changed spacing. A drafting compass from an
art supply store works best. Expect to pay between $10 and $15.
It must have a screw adjustment which sets the spacing between the
points. It must have an extra metal point which can be put in
place of the pencil lead in order to change the compass into
"dividers." When set to a particular spacing, you should feel no
"play" or wiggling if you try to move the compass arms together and
apart. [WARNING! Always verify that the second metal point can
actually be clamped in place of the pencil! I've encountered
compasses where the supplied metal point was the wrong size and
could not be used. ]
Draw one object, and LOTS of circular scratches, from lots of points
on your object. For example, if you were to only draw scratches from
the tips of the letter "V", your hologram would appear as three
glowing dots, and would be very hard to see. Instead, draw the
scratches with your compass placed upon at least nine different places
spread across the "V." The more scratches, the more dots will be in
the final hologram.
Use a sturdy plastic plate, like a piece of Plexiglas 1/16in thick
or thicker. I found that polycarbonate "Lexan" works a little
better than acrylic because the plastic is softer. Someone recently
had good success using the clear plate that came with a small picture
frame. The clear styrene front of CD boxes works well (and some have
a black back, which gives good contrast. For your first hologram try
to get some acrylic or polycarbonate (Plexiglas or Lexan.) Try other
materials later, once you succeed in producing holograms.
DRAW YOUR CIRCULAR SCRATCHES VERY LIGHTLY to start. Once you have
succeeded in producing good holograms, you can try drawing deeper
scratches. Deeper circular scratches produce a brighter hologram.
But if they are a bit too deep, the surfaces inside the scratch will
be shreeded and rough, and the hologram won't work. The scratch
MUST be black and shiny inside.
DULL COMPASS POINTS WORK BETTER. If you compass is new and unused with
extremely sharp points, then you MUST push down very lightly when
making scratches. If you
push down too hard, the sharp
point will create a groove with a flat-sided cross section, or will
tear up the plastic into shreds. Instead your goal is to make scratches
which have a rounded-bottom cross section. Try dulling the sharp points
on 300 or 600 sandpaper. Also, I found that sewing
machine needles work well (they have an intentionally rounded tip.)
Even small nails sometimes work well.
If your compass needle is too sharp, then shallow scratches will work,
but deep ones won't.
AVOID MAKING WHITE, DUSTY SCRATCHES, as these will not reflect light
and will not produce hologram dots. If you sweep the compass point
too fast, or if you push it down too hard, it may chatter and produce
a dusty, non-functioning scratch. If you make a couple white
scratches by accident, don't sweat it. If *most* of the circular
scratches are white, then start over.
Avoid squeaks! If the compass needle makes a squeaking or hissing
sound as you scribe each scratch, then that scratch won't reflect light right.
Each scratch must be smooth inside like a mirror. Scribe your scratches
SLOOOOWLY to avoid squeaks. Rub a very tiny bit of oil on your plastic
plate, it helps.
Tilted / /
compass / /
point / / (Side View)
// ---) Direction of Motion --)
| plastic plate |
Try holding the compass tilted, so the point trails across the plastic
and doesn't dig in and bounce.
Start with a very simple image, like a "V" or "I" or "X" Once you
get this working well, you can scratch your initials, etc. If you
start out with something complicated, you may do a lot of work
yet have your first attempt fail. It's better to do your trial-and-
error with quick and simple images.
It's easier to see holograms having shallow virtual depth, so set your
compass to about 1 or 2 inch spacing between the points. The
first scratch-hologram I ever made was at *fourteen* inches depth!
It was *very* hard to see, and fortunately I knew exactly how to
illuminate and view it, or I never would have seen the image.
Compass point too sharp? The scratches function as reflectors having
curved cross-sections, so if your compass doesn't make polished
scratches with curved bottoms, your hologram won't work. If your
compass point is extremely sharp, then sweep it with low pressure,
otherwise it will create a deep v-shaped scratch which won't reflect
light properly. To make a bright hologram, use a less sharp compass
point with heavier pressure when making the scratch.
Q: WHAT IS THE THEORY BEHIND THIS?
See my SPIE Paper
The brief explanation: curved scratches reflect light as if they were
thin, bent, silvery rods. When you view them in the sun, each scratch
will both focus and also spread the sunlight (each scratch can produce
a "virtual image" or a "real image" of the sun.) You can assemble
a three-D shape from these little dots of sunlight.
Another explanation: each scratch acts as a bent mirror and reflects
sunlight. Each reflection looks like a small
white highlight on the shiny scratch. Each of your eyes sees a
DIFFERENT REFLECTION. Your
brain thinks the two different reflections are really one white dot
located deep behind the scratch. It's like a "viewmaster" stereo
When you draw lots of scratches, each of your eyes sees a different
pattern of dots, with one white dot per scratch. Because your two eyes
see different patterns, your
brain can mix the two images together and make a 3D structure in your
mind. The two images are called a "stereo pair."
For each scratch, the more curved the scratch, the closer the two dots
appear to be. When they are close together, your brain thinks the one
white dot is closer to the plastic surface (it has shallower depth.)
If the scratch is broad
and sweeping, then the two dots will appear far apart, and your brain
will think the one white dot is very deep behind the plastic.
Here's a less-brief explanation: holbrief.html
Here's a paper I presented at a conference:
DRAWING HOLOGRAMS BY HAND at
SPIE Electronic Imaging 2003
The full explanation is contained in this research paper:
W. Plummer & L. Gardner, Applied Optics, V.31 No.31,
Nov. 1992, pp. 6585-6588, "A mechanically generated hologram?"
More info is here: IS IT REALLY HOLOGRAPHIC?
Info about Benton's Whitelight/Rainbow holograms is in this paper:
F. S. Yu, A. Tal, H. Chen, Optical Engineering, Vol.19 No.5,
pp. 666-678, "One-step rainbow holography: recent development
Q: WHY IS IT REQUIRED THAT THE PLASTIC BE BLACK?
The plastic itself needn't be black, since the intent is just to
provide a dark background. These holograms can be viewed either in
"transmission" mode by viewing a distant light source through
clear plastic, or "reflection" mode by viewing an overhead source
bounced off of opaque plastic. I found that the "reflection"
mode gives a much brighter hologram, and using opaque black plastic
improves the contrast. If you use clear plastic, you can place the
hologram on a dark tabletop with a light source above, or hold some
dark paper behind the plastic, or paint the back of the clear plastic
with black paint. These are improvements, not requirements.
Q: HOW DID YOU DRAW THAT CUBE IN TRUE 3D?
> I'd just like to know what's going on with your '3D' cube hologram.
> According to my understanding, if I follow the instructions in your
> article I will generate a flat 2D image of a 2D original, but which
> appears to float above or below the surface as determined by the
> divider spacing. So how did you generate an apparently 3D image on one
My very first 3D object was a big nasty job because I changed the spacing
of the compass in order to change the depth of every single point. Every
single point required a different radius. It took me hours.
But then I found a trick that makes it easy to draw straight lines in
depth (where a straight line can dive inwards in 3D.) You really only
have to figure out the endpoints; you have to carefully position the
glowing white dots at the desired ends of the straight line. For all the
points in between, just draw midpoints! Just place the compass so its
fulcrum point is exactly half way between the previous endpoint
fulcrum-point holes in the plastic, then adjust the compass radius until
you can place a new scratch *exactly* btween the scratches of the two
endpoints you've already drawn. This creates a glowing dot which is half
way between two other dots. It's half way in 3D, and the two other dots
can have different depths. Then do it all again: choose two adjacent
dots and lay another midpoint between them. Keep putting new dots between
existing dots until you've filled in the straight line.
So for the 3D cube, figure out the compass spacing only for the seven
visible corner points of the cube, and draw these seven scratches.
Verify in sunlight that you've made seven glowing dots which look like the
corner-points of a 3D cube. Then place one compass point on the halfway
spot between two existing fulcrum marks that created each of the corners,
and lay a new scratch exactly half way between those two existing endpoint
scratches. (you need to change the compass spacing to do this.) Repeat
this for nine cube edges, nine halfway marks total. Then place the
compass points on the spots half way between THOSE, and draw the new
scratches (18 total). Keep repeating, dividing each line of the cube into
1/4, 1/8, 1/16, 1/32, etc., and where each curved scratch gets laid down
halfway between two other scratches drawn previously. I found that I
could do this freehand; adding more and more scratches between the ones
that were already there. I stopped when the scratches were less than 1/16
inch apart, which made nice solid glowing lines when viewed close up.
For larger holograms viewed from a few feet away, the scratches don't have
to pack so densely.
Now for a REAL trick, figure out how to draw an opaque square. Not just a
glowing square, but a square that hides background objects. Hide your
initials behind it so that you have to tilt your head to look AROUND the
square and see the initials behind it. The secret is to draw incomplete
scratches when drawing the background objects, so that different parts of
the background image go dark at a particular viewing angle.
Q: CAN'T THESE HOLOGRAMS BE VIEWED IN "TRANSMISSION" MODE?
Yes! If you use clear plastic, try viewing your hologram using a
single small light bulb in a dark room. Hold your hologram in front
of your face, about 1ft from your eyes, and hold it so you look
*through* the plastic at the distant light bulb. While observing the
patch of scratches, move the plastic down so that the distant bulb
seems to be a couple inches above the scratches from your point of
view. You should see the highlight-dots light up and form a hologram
in the pattern of scratches.
HINT: if the background near the light bulb is brightly lit, you
may have trouble seeing the hologram. Try turning all lights off
except the single clear bulb. Try suspending the bulb away from
any light-colored wall or lampshade.
Q: HOW CAN I VIEW THESE HOLOGRAMS INDOORS?
- You can't!! Well, it's nearly impossible to see the image unless the
dark, and unless you use just the right light source. If your hologram
doesn't seem to work, you'd better view it outdoors in the sunlight.
ALWAYS view your first hologram in sunlight. That, or use a slide
projector or overhead projector (or a video projector displaying a bright
white field.) You can even use a streetlight
outdoors at night. Once the angles of light are correct and you can "find"
the image, then later you can try using a single distant light bulb
- The best light source should act like the sun. It should appear
small, but be intensely bright like a 300-watt spotlight. A bright
flashlight might work if it's held many feet away. Tracklights
which use hundred-watt (or more) halogen spotlights are ideal. A
clear light bulb can work, but the light is usually too dim. If the
light source is too close to the hologram, it will make the image
blurry and distorted.
- Flourecent fixtures give VERY blurry hologram images. However, if
you happen to be standing under a fixture that has no diffusing
plastic plate in front of it, and which has one tube or two closely-
spaced tubes, then you can use it to view a very blurry hologram.
Stand under the flourescent tube so the tube is perpendicular
to the line between your shoulders, so the tube is in a line going
forward and back. Hold the hologram in front of you and tilt it
up and down until you see a blurry blotch. Tilt the top edge
toward you until the hologram almost goes dark, and it will get
Q: WHAT'S THE BEST PLASTIC?
- Of the types of plastic I've tried, styrene and polycarbonate seem
to work best, but acrylic is the most easy to find. Polycarbonate is
"Lexan(tm)" or "Tuffak(tm)", the bulletproof plastic. Acrylic is
"Plexiglas(tm) or Lucite(tm), perspex and others. Acrylic can be
found at glass shops and large hardware stores. Styrene is commonly
found on the "jewel box" cases of music and computer CDs, the plastic
covers of framed photos, etc.
Softer plastic works a bit better, and
tends not to make the "crunchy white" scratches that sometimes
happen with acrylic. Slightly greasy plastic is best.
Glass won't work unless you can somehow make a
scratch which is smooth and polished. You'd probably have to etch the
scratched glass with hydroflouric acid (nasty stuff.) However, you
could experiment with different types of diamond scribing tools with
glass. I've never tried it.
Q: THIS ISN'T A HOLOGRAM! IT DOESN'T USE COHERENT
Oh yeah? See Why I Call It
The short answer is: if these are not holograms, then neither are Benton
Rainbow Holograms. Abrasion holograms employ the same optics as the
holograms found on credit cards. Mine just have larger spaces between
the zoneplate fringes. All white-light holograms require
size-independent zoneplates in order to reconstruct sharp images using
Q: ARE YOU INSANE? YOU SHOULD KEEP THIS SECRET AND SELL IT!
amasci.com/freenrg/secret.txt for my
thoughts on this.
THIS IS A HOAX, RIGHT?
- I received several messages saying things like "I thought it was a
hoax, but I tried it and it worked!" Huh. It never occurred to me
that people would think it was a hoax. Unfortunately it is impossible
to convince a "disbeliever" of anything. Anything I could say would
just be part of the hoax, right? They'll have to try it themselves.
This behavior is called Pathological Skepticism, and is covered on my
page about Closeminded Scientists.
For the slightly-skeptical, I call your attention to the stereo pair
GIF on the main holo1.html page. It shows a scratched-plastic
hologram along with the glowing 3-dimensional image within its
surface. An ambitious skeptic can look up this research paper:
W. Plummer & L. Gardner, Applied Optics, V.31 No.31,
Nov. 1992, pp. 6585-6588,A mechanically generated hologram?,
I wasn't the first one to notice the phenomena. I'm just the first
to develop the circular-scratch technique into a method for creating
fully detailed hologram images.