Alternate Adjustments
1/4000 sec» Adjustment with Oscilloscope
This adjustment uses the photosensor of the EF-500 connected to an oscilloscope to check the 1/4000 sec. shutter speed. Before this adjustment, adjust the curtain travel time with the EF-500.
Pins 2 and 6 are the "B Line" connection
Oscilloscope m . \
Variable Resistor Adjust to SKn-SOKT)
Pins 2 and 6 are the "B Line" connection
Oscilloscope m . \
Variable Resistor Adjust to SKn-SOKT)
Procedure
1 . Connect the EF-500 photosensor to the oscilloscope as shown.
2. Set the EF500 to EV12 and K14.03. Put the photosensor in the film aperture.
3. Set the camera to a long shutter speed or bulb, and release the shutter. While the shutter is open, adjust the variable resistor so the line on the oscilloscope is on 0.5V.
4. Reset the EF500 to EV15 and the camera to a 4000th, and release the shutter.
5. Read the width of the waveform at 2V. It should be 294 us.
6. Adjust VR8 so the width at 2V is as close as possible to 294us.
Note Using the EF-500 to adjust 1/4000 sec. will result in a slow shutter speed (about 0.37ms). The EF-500 can be used by taking an average of several good cameras. Another possibility is adjusting at 1/1000sec. as a midpoint, but since the accuracy of the EF-500 is +0.1EV, this would allow a +0.4EV at 1/4000 sec. even if the 1/1000 sec. adjustment was perfect (0.98ms). Because of the possible error, we do not recommend this method.
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