Archived posting to the Leica Users Group, 1996/08/03
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Pasi, I wanted to do tests outside today to take advantage of good natural light. Unfortunately, it rained today and I was unable to set up my experiment. Paper gray cards and Leicas are not waterproof. Please stay tuned. I wanted to do these tests over a wider range of light intensity and composition.. I agree with you that a clever circuit without a transistor might work. However, I was unable to get someone at Leica to speak with me. The service department in New Jersey referred me to Germany. I do not have the MR4 meter, but am working on the assumption that the meters in the SL2 and M5 cameras have similar circuits. Chris At 09:54 PM 8/3/96 +0300, you wrote: > >>From: "C.M. Fortunko" <fortunko@boulder.nist.gov> >> >>Frankly, I do not believe that any of the cameras using only a single >>mercury cell (SL, SL2, and M5) can be regulated. This is because there is >>not enough voltage to make a transistor work. I assume that the CL has a >>similar meter circuit to the M5, although it was made by Minolta. > >For making the compensation work, it is enough, if there is one element >in the circuit that is not linear. It may be a diode or a non-linear >resistance such as a light dependent resistor. Effectiveness of the >compensation is achieved both with the type of components used >and with correct design. >There are tradeoffs to make between meter accuracy, simple design, >power consumption, meter sensitivity, supply voltage and resistance to >battery wear. >I suppose the MR meter is a combination of simple components >and clever design. I'm waiting for your test results with great interest. > >Best regards, > >Pasi Ohtonen > > >