Re: Kodak HIE and #87C

[Joshua_Putnam <josh@xxxxxxxxxxxx>]

"Tolga Yayalar" <tyayalar@xxxxxxxxxxx> writes:

>I've been using #25 filter quiet while but recently I purchased kodak's 87C
>filter. I've just developed my first roll, I was shocked with the results. I
>had shot the roll on a sunny day with some clouds. In some shots I also used
>#25 filter  just to be able to compare later. The ones that I shot with 87C
>are almost completely black, I can see the image but they are so dense that
>edges of the film is effected too. But the ones that I shot with #25 are
>just as I expected. I used 400iso when #25 is atteched to the lens and 12
>iso with the #87C. 

Do you mean you were metering through the 25 red, with your film
speed set at 400?  That's the setting I would normally use for
metering through a 25 red, and it gives results equivalent to
using Sunny 16 with a film speed of 50, e.g. 1/60 at f/16 in
bright sunlight.

If you then tried metering through the 87C, your camera's meter
would see almost nothing, while the film would receive all the
infrared that your meter does not respond to.  A film speed of 12
would be appropriate for Sunny 16, that is, not metering through
the filter at all.  Your proper exposure would be in the range of
1/15 at f/16, but your meter would think there was almost no
light, and would take a very long exposure instead.

Since most meters don't respond predictably to IR as deep as the
87C passes, there is no reliable filter factor for that filter.

-- 
 Josh@xxxxxxxxxxxx  is  Joshua Putnam / P.O. Box 13220 / Burton, WA 98013
                     http://www.wolfenet.com/~josh/
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