Rate this post by selecting a number. 1 is the worst and 5 is the best.

Author Message   Aphototaker Tinkerer Username: Aphototaker Post Number: 250 Registered: 12-2009 Rating: N/A Votes: 0 Posted on Monday, August 16, 2010 - 10:56 pm:    Most of what Camerawiz wrote appears to agree with the basic method as I understand it. In his description of the method, VR1 changes the slope of the meter's response line and VR2 changes its vertical offset. However, I don't think the following is correct. "place a 47 0hm resistor across the dedicated flash terminal and ground, close the meter switch and adjust the meter until it reads f4." The correct value of the resistance to get f/4 reading is 4.7 KOhms. This the equivalent resistance of a Canon dedicated Speedlite when set at f/4 aperture. When this resistance is applied between the hot shoe contact and ground of the camera and the shutter is released, the lens should close down to f/4.