Archived posting to the Leica Users Group, 2001/09/16

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] Filter Factors
From: Shel Belinkoff <belinkoff@earthlink.net>
Date: Sun, 16 Sep 2001 11:53:03 -0700

Everything I've read, including the information sheet packed
with my new filters, indicates that the filter factor for a Medium
Yellow filter (Y2) is 2X, or 1 stop.  So, while checking 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 about 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.

Since I'll be doing 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:belinkoff@earthlink.net
- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html

Replies: Reply from "Don Dory" <dorysrus@mindspring.com> (Re: [Leica] Filter Factors)
Reply from Mark Rabiner <mark@rabiner.cncoffice.com> (Re: [Leica] Filter Factors)