Re: Filter/Speed/Meter & DON'T meter using a Nikon Camera

["phillip geller" <filje@xxxxxxxxxxx>]

Also, For the person who tested the Nikon F1 nad F2’s meters to try to prove
they are sensitive to IR light you may very well be correct, however, I
would like to point out the following:

1) The F1 uses CDS metering cells not SPD like you claim. The two different
metering cells have very different light sensitivities and characteristics.
The first two Prisims for the F2 also used CDS cells; it was not until the
DP3 that Nikon switched to SPD cells. It should also be noted that all the
Nikkormats used CDS cells.



it was an old canon f 1 if I was the one you're quoting and yes I stated
that it
uses cds and is more sensitive by several stops.I can put
an 88a on the thing with the meter at an ei of 200 and shoot konica ir
without bracketing.

 All the new F1's and the A series and T series canons use spd's with
blockers.

The cds meters do not have blockers and I recall old descriptions that they
primarily see the yellow-green part of the spectrum however, they do see IR
as well
and when I get my old F 1 back from the fixit shop and the sun comes out, I
will
test out the response at low color temps.

BTW
I dug out my recent copy of Edmund Industrial Optics and found Ir cut off
filters.
There is a chart that shows the transmission for a visible spectrum pass
filter.
 The cut off is sharp and is 85 to 90 percent at 700 nm but it still lets
some
light through at up to around 750 nm.

There's also a listing for a Schott BG 38 that passes uv and the visible
spectrum
and almost no IR.

phil

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