behind what I’ve been working on is basically a small holocamera.
I originally came upon the idea as something I can teach for middle school
grades (5-8) at my sons’ school. It’s turned out to be very useful for general
(small scale) hobby holography at home too. I don’t have space available for a
regular darkroom setup - the holography project has to share space in our
high-tech family room, which is home to many other hobbies (4 computers total, 3
ham radio stations, model rocket building, etc.) all in a 16x24’ room.
critical ingredients for a daylight holocamera,
besides providing a stable optical setup, are the ability to set up the
mirrors, object, film position, and laser in room light, then close the box and
allow the film to be exposed.
I built a
small table (1' x 2') using 4 cinder blocks,
that are topped
with a piece of plywood. A large cardboard box sits on the plywood, and the
rest of the table is built inside the box.
Vibration isolation is provided by 13” bicycle inner tubes next to each other
underneath a 12” x 24” x 4” cast slab of concrete with smooth marble floor tiles
on top for a flat surface
cardboard box is not mounted to the table - the inner tubes and table are inside
the box. The box has a tight-fitting lid.
out a way to mount a piece of film in a glass sandwich inside an old 5 x 7 cut
film holder. 4” x 5” PFG-01 film is sandwiched between 4” x 6” pieces of glass,
which is held in a modified 5x7 sheet film holder
The film is
loaded in the dark (a bathroom with no windows) and the dark slides are
inserted to exclude light.
There's a cutout section on the side of the box. I used 8 layers of black
plastic trash bags to make a vibration-isolated light-blocking 'window' where
the plate holder can be inserted
I made a
metal guide for the film holder to fit thru which is mounted in the plastic
plastic ‘window’ provides light blocking while also allowing relative movement
between the box which is non-isolated and the slab on the inner tubes which is
I built a
shelf out of steel angle which holds the film holder and the object
This can be used frontwards
for transmission and reflection holo’s.
holder is inserted in the guide and clamped to the object holder with small
optical components are mounted on 3/*’ IPT pipe flanges and nipples. I epoxied a 2” square piece of plexiglass
to the bottom of each stand for a stable surface to the marble.
laser I use a small 5mw diode laser powered by 2 AA batteries. To keep
everything small so it fits inside the setup, I’ve assembled the laser diode, a
20x microscope objective, and a Radio Shack meter type shutter together onto a
the beam is expanded right at the laser, I have to use large mirrors (4”x5”) mounted
on the optical stands. I have one that serves as a beam splitter - it’s about
70% reflective. Here’s a typical setup for a transmission holo:
I set up everything inside the box, put the cover on, then remove the dark
slides from the film holder. I use a switchbox with a long cable to time the
exposure with the Radio Shack type meter shutter. After the exposure's done, I
slip the dark slides back in. Then I can open the box and remove the film
I do daylight processing as well, using
a color print drum. I load the film into the drum in a dark (bath)room, then
process in daylight using D-19. I use a stop bath step, after which the rest is
done in daylight. I use the JD-2 bleach, which seems to last forever.
October 21, 2003
I took some digital pictures
of a hologram I made with the holocamera setup. This is one of my best. It's a
ceramic 'Minnie Mouse Blowing a Kiss' (purchased in DiIsney World). The kiss™ is
mounted on a tiny wire spring. I thought it was likely to move and apparently it
did. Although the kiss is red, and bright when viewed in laser light, it came
out black in the holo. If you look closely at the spring, and follow it down to
the rest of the statuette, you can see where the spring changes from black to
shiny silver! Very interesting effect!
It was exposed for 136 seconds. This is a split beam transmission hologram on
PFG-01 developed with JD-2. The resultant density was 1.27.
November 23, 2003
Wireless Shutter for Holography
Recently I’ve been making holograms with diode lasers and helium neon lasers in
the 5-10 mw range. I’ve developed a technique for making holograms without a
darkroom (see my pictures posted at http://www.dragonseye.com/holography/guests/tonybrockfisher/).
A critical component for this is a remotely activated shutter. I made electric
shutters in the usual way from a Radio Shack meter (#270-1754). The process for
making a shutter from this meter is documented elsewhere. I had this connected
to a small project box with a battery, current limiting resistor, and switch.
The control box was connected with small wire to the shutter itself which sits
on the optical bench.
This system worked, but the wire was always a hassle. First, I worried about it
transmitting vibrations to the table. Second, I was always tripping over it. And
finally, it was always getting tangled up. I definitely wanted to find a way to
My solution was found cheaply in the form of the miniature Radio Control cars
that are so popular. Priced from around $20 or less, these little cars have a
transmitter unit and a 2-channel receiver in the little car. Here’s how to adapt
the circuit from the car to the shutter. The car I bought was only $12, and was
called ‘microEnergizers’. It had a red LED inside the car that lit up anytime
the car was moving.
The first thing is to put batteries in the toy and play with it a while to make
sure it works - have some fun! Remove the car body. This reveals a clear plastic
cover which hold the postage-stamp sized circuit board in place. Carefully pry
the clips that hold the clear lid in place to remove it. With the cover removed,
the circuit board can also be removed carefully - it has many wires attached to
it. Before removing any of the wires, make some notes to yourself so you know
where the wires are attached. You should find 2 wires that go to the motor, 2
very fine copper wires that go to the steering solenoid in the front, and two
wires that go to the tiny rechargeable battery. My car also had 2 wires going to
the small LED. Remove the battery - it should pop out. Using a low-wattage
soldering iron, unsolder the battery wires at the contact clips (remember which
is (+), it is usually red and goes to the button end of the battery). Also
unsolder the fine copper wires for the steering and the motor from the circuit
board. If there’s a LED, unsolder it but leave the wires.
In my setup, I used the LED output to drive the meter. This was convenient
because the LED goes on whenever the forward or reverse buttons are pushed. If
you have a car without the LED, you’ll have to choose either the motor circuit
or the steering circuit to drive the meter.
Whichever circuit you choose, connect it to the meter, using the 15K resistor
that comes with the meter. Connect a small battery (AAA or 1.5v N cell) holder
to the battery connections on the circuit board, observing proper polarity. You
can then stick the battery holder to whatever type of mount scheme you have
using double-sided foam tape.
Insert a battery into the battery holder (observe proper polarity) and test the
unit. When you press the appropriate button (depends on whether you used the
motor circuit or the steering circuit), the meter/shutter should open.
The car circuit draws very little current, so it should last quite a while - but
remove the battery between shooting sessions.
March 21, 2004
These are my 'latest works', H2 reflection copies. 11 mw Hene, PFG-01 and
8E75 (varied) processed in D-19. These were done on my 1'x2' table. Originals