Modifying your camera so it can meter IR WAS: Is this true?

["Rolland Elliott" <rolland_elliott@xxxxxxxxxxx>]

Well, it's quite a simple concept. 99.9% of all modern AF, Auto exposure, 
auto everying, wiz bang cameras use SPD cells for metering. These metering 
cells all are very sensitive to IR light. Camera manufacturers put a bluish 
green filter infront of all the metering cells and this makes them for all 
practical purposes only reliable for visible light metering.
Don't believe books that tell you modern camera meters aren't sensitive to 
IR light. The fact of the matter is they are sensitive, but camera 
manufacturers SPECIFICALLY make them to NOT work with IR light by inserting 
this blocking filter. There are some Wierdo cameras, like the F5 that use a 
CCD, but these too are sensitive to IR light and use a blocking fitler. In 
fact this is what video cameras use to record light. Hence video cameras 
need a IR block filter also.  In fact the sales brochure for the F5 has  a 
cutaway view of the camera showing this filter.

Just replace the blue gree IR block filter with a red filter and you have a 
very good IR meter.

Of course most people are not going to take apart their camera, but you 
asked.

Peace, Rolland
P.S. Legal Disclaimer: If you do take apart your camera and break it. It is 
your fault, even if my advice was bad.



Subject: RE: Is this true? (hi dani)
> > Some folks here on the list have
> >modified their cameras to do a better job (metering IR).
>How?

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