The following procedure should be used to perform those parts of the Camera Lab 2 experiments which require the use of a virtual oscilloscope (O-SCOPE).


Step 1 – Insure you have a light probe, a black cable, and a standard flashlight at your work table.  (Also, each person should have their camera !!)


Step 2 – Connect one end of the cable to the light probe.  Connect the other end of the cable to the back of the computer on ‘Ch 0’.  (The rightmost of the three larger round connectors on the O-SCOPE card in the computer).


Step 3 – Double click on ‘Virtual Bench – Scope’ on the desktop.


Step 4 – Load the default settings.  (You should to do this twice to insure the default settings have been completely loaded.)

-         Edit à Load Settings

-         Select ‘default.sco’

-         à Open


Step 5 – Make sure ‘Run’ is in the OFF position when you are changing settings.  Only ‘Ch 0’ should be active for this experiment.


Step 6 – Set the ‘Timebase’ to 2 mSec/Div.


Step 7 – Set the ‘Volts/Div’ to 5V.


Step 8 – Set the Trigger Source (Src) to ‘Ch 0’.


Step 9 – Set the Trigger level and it’s position in the timeline.  This is denoted on the screen by a small + symbol.  You will need to start with the Trigger centered.

-         à Controls à Trigger à Center  (Repeat until + is centered)

-         à Controls à Trigger à Increase  (Repeat until Trig 2V)

-         à Controls à Trigger à Move Left  (Move to 1st vertical grid line)

-         Note: The quick keys may be helpful.  (ie.  Shift + ß )

-         The screen should look like something like this:


Step 10 – Click on ‘Single’ to enable the capture.  Before you begin you may want to press the button on the probe and shine the flashlight in the end to test your settings.  You should see a square wave that starts at the trigger mark.  If you experience difficulty you may need to reload the default settings or possibly restart the application and repeat the above steps.


Step 11 – You should now be ready to capture the shutter speed.

-         First, wind the camera shutter mechanism.  (Your TA will show you how.)

-         Turn on the flashlight and point it directly into the camera lens as shown.



-         Hold the light probe inside the camera carefully lining it up with the lens.

-         While holding the light probe button down, click ‘Single’ then push the shutter release button.

-         Release the light probe button and remove the light probe from the camera.

-         You may need to do this a few times to get good results.

-         The capture should look something like this:



Step 12 – Record your results and repeat this for each camera in your group.

-         For printing you will want to change the Background to white, the Foreground to gray and the ‘Ch 0’ to Black.  This can be done by:

o       Edit à General Settings à Display

o       Modify Background and Foreground setting appropriately and Apply.

o       Edit à Channel Settings

o       Modify the ‘Ch 0’ color under the Acquire tab.

-         You can capture the active window by pressing ‘Alt+Print Screen’ and pasting the image to Word.  Be sure to label each plot.  (Save your work!)


Step 13 – Capturing the Flash duration.

-         You will need to change the Timebase but the other settings should remain unchanged.

-         Remember ‘Single’ needs to be OFF to change settings.

-         Set the Timebase to 500mSec/Div.

-         While holding the light sensor button down, direct the flash at the end of the light probe.  You should hold the light probe at least two hand-spreads in front of the camera flash bulb.

-         Record your data as you did in Step 12.