Everything I've read recently, including the information sheet packed
with my new Pentax SMC filters (my thanks to those who helped me get
these great filters) suggests that the filter factor for a Medium
Yellow filter (Y2) is 2X, or 1 stop. So, while calibrating my gear
this morning I decided to check the needed exposure compensation using
two Pentax spotmeters, the digital Zone VI modified meter and the
standard, but calibrated, Spotmeter V. Both showed that the needed
exposure compensation would be about 1/3 stop more with the filter
than without. I metered off a white truck, the overcast sky, and a
building. Always 1/3 stop. Off some other colors there was a slight
difference in the readings between the Zone VI meter and the standard
meter, which is to be expected, but in no circumstance did either of
the meters indicate the need for an additional full stop with the Y2
filter.
I suspect this discrepancy may be due to the sky being overcast and
there being less blue light for the filter to absorb.
However, using the meter on the LX, I'm shown a 1-stop compensation.
But the LX meter, and other built-in meters, don't show fractions of
exposure readings, even though the camera may actually make the
exposure between one and another shutter speed. Fr example, I've used
the LX to make a normal exposure, and then used exposure compensation
to increase or decrease the exposure by 1/3 stop. Sometimes there was
a change in the readout, other times not, depending, I assume, on how
close the difference in exposure was to the point where it would show.
So, it seems, using the meters built into the camera, while giving
accurate exposure, won't necessarily tell me what the compensation
was.
Since I'm going to be some work with hand-held meters and manual
cameras, can we discuss this situation a bit. One thought that
crossed my mind was to make the exposure readings off a grey card,
which I'll try later when I'm outside and away from the computer. Any
thoughts on that idea.
--
Shel Belinkoff
mailto:[EMAIL PROTECTED]
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