Re: Opinions on a camera.

In article <pan.2007.04.07.19.25.31.398765@xxxxxxxxxx>, ray
ray@xxxxxxxxxx says...
On Sat, 07 Apr 2007 14:15:39 +0100, Rob Morley wrote:

In article <2lMRh.8809$cj.7687@xxxxxxxxxxxxxxxxxxxx>, Fat Sam
samandjanetknox@xxxxxxxxxx says...

Aaaah. I would never have realised that the makeup of a battery could affect
the workings of the device it's powering.

It can be quite a problme with older equipment that used mercury cells -
these are now banned. They were used because they gave a very flat
voltage throughout their life, so there was no need for compensation
circuitry. The problem is that they were 1.35V - using a 1.5V cell will
tend to skew readings. Also alkaline cells lose voltage throughout their
life - silver oxide is better but runs at 1.55V. I recently bought an
old mechanical Praktica that has TTL metering, and I'm going to try
using a silver oxide cell with a diode to restrict the voltage, but with
a fully mechanical camera it's not that much of a problem - I can always
use a hand-held meter or just compensate a couple of stops for the
skewed reading.

I recall having done some web searches last year - there is a company in
Britain (as I recall) that has 'adapters' for the alkaline cells - it
seems they also control the output voltage and greatly extend the life,
though I don't recall if it was indicated to be as good as the original
mercury cells.

They also cost rather more than I paid for the camera :-)
.

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