Paul C. Buff, Inc. Technical Forum

Hi,
I am using the Cyber Commander as a light meter with three Einstein. I meter the main light, the second and third fill lights. Then I perform the 'All' light metering for the total reading. In either cases (i.e. if I meter the main light or All of them) when I set the same f/stop in the camera the lights are over-exposed of about 2/3 ot 1 f/stop so I have to increase the aperture in the camera to avoid over-exposure (e.g. frpm 8 to 11). I do not have another lightmeter to calibrate so I would like to know how to match the meter to the camera settings to avoid a discrepancy of about 2/3 to 1 f-stop between the lights and the camera.

Many thanks

First, make sure your ISO matches that of your camera (your shutter speed will also need to match if you are in bright ambient light). These are found in the upper left corner of the Cyber Commander, and can be changed in the SETUP>FLASHMETER screen. Also in that screen, you will see the letters "CAL" in the upper right. The value directly under this should be +0.0f.

Also, to be sure, you are metering at the subject's position and the dome is facing the light or camera?

I triple checked that: ISO, speed, calibration set at +0.0f. I also took different reading as you described with no much difference among the reading. In spite of that the camera still calls for a closer f/stop to avoid over-exposure.

Do you have any hint on how to compensate for this?

Thanks for your prompt reply.

If it is consistent, you can change the CAL to + or - whatever you think is best.


One other note. The numbers after the apostrophe are just as important as the ones before it. If you get a reading of f/5.6' 9, you are much closer to f/8 than to f/5.6. In fact, you are 9/10 of a stop above f/5.6 and 1/10 stop below f/8. Many people would expect the next numerical value after 5.6' 9 to be 5.7' 0, however, the next value would be 8.0.

5.6' 3 would be 1/3 stop more than 5.6 (a.k.a 6.3 on your camera), and 5.6' 7 would be 2/3 stops more (a.k.a 7.1 on your camera).

Once you take an ALL meter reading, you can raise or lower the lights collectively to an even f/5.6 or f/8 or whatever. Take the power to an even f stop, and try again.

Dunno if it applies, but the Cyber Commander's light meter seems to be very particular with the direction of light. The dome does not seem to pick up light from the side as well as light coming in straight from the front.

If you are taking reading by facing the meter towards the camera (like I do with my light meter), the Cyber Commander will vary greatly depending how much of an angle that particular light might be from a direct line to the front.

My Sekonic reads well weather its facing the camera or if its facing the light.

With the Cyber Commander, I need to make sure the dome is facing directly into the light source.

With that in mind, the Cyber Commander, my Sekonic, and my camera are all as close to perfect and consistent as I would want to expect.