[rollei_list] Re: Batteries

Hi Eric,

> My own conclusion after trying them all is either the CRIS adapter or
> using silver oxide replacements and recalibrating to the higher (but
> consistent and long-lived) voltage. I find the Z-O cells too short
> lived to count on... often just about dead right new right from the
> package...

I have come to the same conclusion about ZO batteries.  I won't use them.
But, I have found that simply "recalibrating" (which means different things)
to a higher voltage battery does not always yield the "correct" results
across the entire exposure range.

What is typically done with "recalibrating" is simply adjusting the metering
system (via mechanical means or some electronic means) for the difference in
voltage "offset" at one point in the metering range.  This may or may not
work for a particular camera.  For the Canon F1 for example, it does not.
It may be close enough for most of the range though.  And the Canon F1 is a
mechanical "recalibration".  What I've found, is for mechanical
recalibration, there is always significant error for a good part of the
range, typically the ends if you calibrate for the middle.  For electronic
recalibration, that is very dependant on the circuitry, and it stands a
better chance of higher accuracy across the entire range than a mechanical
recalibration.

Let's not confuse accuracy with consistency.  Even if a meter is inaccurate,
it can still be consistent.

Some cameras, like the Canon EF, are simply plug and play.  The circuitry
has a wider tolerance for input voltage (some claim it has a voltage
regulator, but there is no proof of that, and I have the schematics and
circuit boards etc., and find no regulator, unless it is embedded in the one
IC in the circuit, which I doubt), and the meter readings are the same for
mercury or silver oxide, with no adjustment.

Regards,

Austin
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