It's super leightweight, super cheap and uncomplicated.
IMHO the best thing about it is the method to hold down the pages.
I use two Canon Powershot cameras which I power via two voltage regulators
(LM350). Although the cameras have 4.3V printed near the plug for external
power supply, I found out that they start working somewhere above/around 5V. Since
four AA batteries amount to 6V I run both cameras somewhere at 5.8V which
seems to be fine. As the main power supply I use a universal adapter rated
for 2A which I've set to 9V. Attached are the two LM350 each configured with
their standard circuit (one potentiometer 5k, two capacitors, one resistor)
It seems that you need to use regulators that can provide the 2A for short
periods that the original Canon power supply provides. I used weaker
regulators before which did not provide enough current once the motor for
the zooming kicks in. As for the power plugs: outer diameter is 4mm which
Holding the book:
I've cut one Leitz folder in two and used duct tape to fix the halves to L-shaped
book stands like this: L\_/_I (The boxes in the pictures only support the cameras)
This setup is quite sturdy since I also used duct tape to connect the book
stands at the bottom - this way they don't move once pressure is applied
from the top.
Holding down the pages:
This is the best part in my opinion.
I got some 8x8mm aluminium sticks (hollow) and cut them to convenient
lenghts. Duct tape again and a bit of bike inner tube were used to create
the size adjustable setup seen in the picture. One hand is enough to hold down the pages.
All the aluminium weights about 150g - no kilograms needed to be lifted.
Getting the pictures:
I attached both cameras to my computer.
I use gphoto2 2.4.9 and the following perl script to get the images from both cameras. The
timing is such that once I have turned the page the images are usually
transferred. I need to remove the flash cards from the cameras in order to
get "/main/settings/capturetarget 0" working with gphoto2.
So no batteries needed plus no wearing of flash cards involved.
The way the script is written, I only have to push ENTER to take the two
pictures simultaneously. In combination with the usb keyboard in the
picture, this is really convenient. (Possibility: there are seperate usb
number pads. That would take less space since I only need the ENTER key.)
Setup the camera, to be run for each camera:
Code: Select all
gphoto2 --shell --port $@<<EOF
set-config /main/settings/capture 1
set-config /main/settings/capturetarget 0
#set-config /main/capturesettings/zoom 3
set-config /main/imgsettings/whitebalance 6
set-config /main/imgsettings/imagesize 1
set-config /main/imgsettings/iso 2
set-config /main/capturesettings/shootingmode 2
set-config /main/capturesettings/aperture 3
set-config /main/actions/focuslock 1
Code: Select all
$pad = "%.3"."d";
system('/opt/gphoto2/bin/gphoto2 --filename "'.$number.'-%m-%d-%H-%M-%S left.jpg" --port "usb:002,043" --capture-image-and-download &');
system('/opt/gphoto2/bin/gphoto2 --filename "'.$number.'-%m-%d-%H-%M-%S right.jpg" --port "usb:002,042" --capture-image-and-download &');
Code: Select all
while [ $instances -gt 0 ]; do
instances=`ps -e -o command|grep "^$name"|wc -l`;
aplay /home/m/permanent/sounds/submarine.wav &
Overall cost except cameras should be about 10 EUR.
BTW: The big speaker magnet in the picture is only there to hold down the
stick while I take the picture