Two Camera Field Sequential 3D Circuit Design for use with Stereo Microscope

 

By Gerald Heine

 

Premise:

 

Since I saw my first 3D movie, “It Came From Outer Space”, in 1953 I’ve been interested in making my own 3D movies. I got my first 3D camera in 1954, a Bell and Howell Three Dimension Company Colorist, which I still have.

 

I was interested in taking 3D pictures through a Stereo Microscope, but have not seen anything that could do this. The Field Sequential system of 3D movies has brought a new interest in 3D movies. Many of the films originally shown in IMAX theaters are now available in the Field Sequential 3D format.

 

The Field Sequential method of 3D works only on TV screens that use cathode ray tubes (CRT) for the display. It utilizes the two interlaced fields used to display the picture. The TV picture is made up of 525 scanned lines. The screen is scanned twice, once for the odd numbered lines and again for the even numbered lines. These two fields can be separated and one used for the right eye and the other for the left eye of a 3D picture pair.

 

Designing the Circuit:

 

In setting out to build a device for taking 3D video through a microscope I looked for resources on-line. Here are some of the sources I found very helpful:

 

Easy PCB (Printed Circuit Board) Fabrication, Using Laser Printer Toner Transfer

http://www.fullnet.com/u/tomg/gooteepc.htm

 

Robot Room - Making Printed Circuit Boards

http://www.robotroom.com/PCB.html

 

ExpressPCB - Free PCB layout software - Low cost circuit boards

http://www.expresspcb.com/

 

Stereo Video

http://www.petesprojects.com/stereo-video/index.htm

 

Razor3D - Video Gear

http://www.razor3donline.com/3dvideogear.html

 

Jameco Electronics

http://www.jameco.com/

 

Radio Shack

http://www.radioshack.com/

 

 

The primary integrated circuits used are the LM1881 sync separator and the CD4066 switch. The LM1881 has an output that will go high or low depending whether an odd or even numbered scan line is being received. This information can be used to separate two video signals for the left and right stereo images using the CD4066 to switch the odd and even video scan lines.

 

 

To download a high resolution view of the circuit click the above image.

 

A left/right manual switch is needed because there is know way to control which (left or right) image will be the odd and which will be the even scanned lines.

 

Parts List:

 

Item                                                     Quantity           Ref                   Source

 

LM78L05                                            1                      U1                   Jameco 51182

 

LM1881                                              1                      U2                   Jameco 107140

 

CD4049                                               1                      U3                   Jameco 13055

 

CD4066                                               1                      U4                   Jameco 13186

 

Electrolytic Capacitor 100uF                1                      C1                   Jameco 29963

 

Ceramic Capacitor .1uF                       2                      C2-C3             Jameco 15270

 

Resistor 680K Ohms                            1                      R1                    Jameco 31501

 

DPDT Switch                                       1                      S1                    Radio Shack 275-614

 

Power Jack                                          1                      J1                     Radio Shack 274-1563

 

Phono Jack                                          3                      J2-J4                Radio Shack 274-346

 

1/8” Stereo Jack                                   1                      J5                     Radio Shack 274-249

 

Project Box 6x4x2                               1                                              Radio Shack 270-1806

 

9V Battery Holder                                1                                              Radio Shack 270-326

 

Hook-Up Wire 22 Gage Solid              1                                              Radio Shack 278-1215

 

9V Battery Connector                          1                                              Ispyvideo.com

 

Making the Circuit Board:

 

I have made many printed circuit boards before, but not by the method used for this project. I used the Laser Printer Toner Transfer Method. See the links above for more information on this method.

 

Etched side of circuit board.

 

Etched side of circuit board mirror reversed for use in the printed image transfer to copper clad board.

Click the above image to download the large image for printing.

I used 32% image size in Paint Shop Pro to print the image.

 

Component side of circuit board

 

Component side of circuit board mirror reversed for printing

Click the above image to download the large image for printing.

I used 32% image size in Paint Shop Pro to print the image.

 

 

 

 

The board I made using the Laser Printer Toner Transfer Method.

 

 

Completed 3D Video Sync Box

 

Microscope Setup:

 

The video cameras I used for this project were a Sanyo VCC-3972 which is capable of  using external sync and a Sanyo VCC-6574A. One camera must be capable of using external sync, so that the scan lines of the two cameras are in sync. I adjusted the back-focus adjustment on the two cameras so they will focus at the same distance. I used a camera lens and infinity focus on an object to do this.

 

The two cameras are connected to the microscope using a telescope adapters the ScopeTronix C Mount for Video Cameras, which has an inside diameter that I found would just fit over the eyepiece of the microscope for eyepiece projection. I used a 5mm CS to C mount adapter between the ScopeTronix adapter and the video camera. One source for this is SpyTown.  A rubber-band was placed around the two cameras to help stabilize them.

 

The external sync of  one camera is connected to the video output of the other camera through the use of a T-connector and a short cable. The video output of each camera is then connected to the 3D Video Sync Box constructed here. The output on the Sync Box is connected to a DVD recorder and monitor. 3D shutter glasses are connected to the input provided on the Sync Box. While observing the monitor the switch on the side of the Sync Box is set to correct the picture for the left and right eye. The microscope ocular separation is then adjusted for the proper convergence of the images.

 

I adapted a mechanical stage for use on my microscope so that I could motion scan the image being observed.

I used a microscope with a 2X objective and a 20X eyepiece. The microscope, mechanical stage, and eyepieces were purchased from the SurplusShed.

 

 

Microscope Setup

 

The Results:

 

To download a sample of a 3D movie I made with this system click below:

You will need 3D shutter glasses and a 3D converter box to view these files. A good source for this is Razor3D. They offer a package deal that includes one DVD movie. I recommend “Encounter in the Third Dimension” or “Ultimate G’s”. These movies were originally shown in IMAX theaters. This system only works with CRT (Cathode Ray Tube) type TV sets, it will not work on LCD TV sets.

 

I also made a short video with the two cameras set for normal 3D (non-microscopic). The cameras are just set side-by-side and fitted with 12.5mm lenses.

 

 

 

Microscopic 3D Movie - 36mb - This file is in DVD format for burning direct to DVD with Nero or other DVD burner program.

 

Email me at heinega@saclink.csus.edu

 

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