s an example of changing the calibration in an older light metre.
http://www.graphic-fusion.com/lunapro.htm
2/3 of the way down
s an example of changing the calibration in an older light metre.
http://www.graphic-fusion.com/lunapro.htm
2/3 of the way down
BrianShaw
Check to make sure I'm correct, but I think a variac is more useful for this application.
Leigh
Both rheostats and Variacs can be used to adjust voltages.
Rheostats work with both AC and DC. Variacs are AC only.
Both technologies are available for very high power applications.
Well, sometimes it's the second language thing sort of pops its head..... To be little more clear, I used this mini "dimmer" (if you will) to construct a 20V volt supply. At the time I could only obtain a 30V gadget and I was able to turn it down to desired volts. This was 20yrs ago...and I'd presume it was DC.
Les
Im with Nathan on this. Nothing beat the Sunny 16 if used properly. Here in New England where the Sun in the summer is above the 45 degrees I use the rule all the time even in the beach between 10 and 2. Of course, if Im in FL in the middle of the summer in a white sands beach I will pull the meter out because not only I know the sun is a lot stronger. There are also a lot more of reflected light hitting the subject.
Regarding the Arduino project, take a look also at the sensors from a company called TAOS. Nowadays all the almost-linear behavior of the analog front end is pretty much corrected by the time it gets the data to the interface of the sensor.
I do enjoy electronics but sure I rather buy a Sekonic digital light meter here in the forum that typically is within 0.1 EV of error.
Exactly what I am talking about.Originally Posted by cowanw
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