if you are metering through the lens, then metering with the filter in place
is best. after that, the filter density depends on the lighting conditions
and the amount of water blur you want. for me, anything less than 4 seconds
doesn't have the right effect. my usual is 8-20 seconds exposure times, even
in the middle of the day in bright sunlight. to get those shutter speeds at
a reasonable aperture of f11-f16, i have 3, 6, and 10 stop ND filters that i
frequently place a polarizer on top of, and a 2-7 stop variable ND filter
that doesn't allow a polarizer.
Herb..
----- Original Message -----
From: "Stephen Moore" <[EMAIL PROTECTED]>
To: "Pentax List" <[email protected]>
Sent: Thursday, July 14, 2005 8:54 AM
Subject: Setting exposure with ND filter
Here's a hypothetical situation: I want to shoot
some waterfalls and other moving water using
ISO 50 transparency film, and want to slow the
shutter speed to get a nice blur on the water.
Conventional wisdom says an ND filter (assume
a 2-stop) is how this is done.
So does one meter the scene before or after the
ND is in place, i.e., adjust exposure for the
desired medium tone, put the filter in place, and
then slow the shutter by 2 stops? Or simply meter
through the filter and use the desired shutter speed
(1/4 to 1/2 sec?) as a baseline for adjustment?
