"Elliott, Rolland" wrote:
>
> "I'd almost take the "meter without the filter" and file it under myth,
> too."
>
> All Canon and Nikon and other 35mm SLR's that use SPC (silicon Photo diodes)
> for metering (which is 99.9% of them) have Infrared block filters in them
> that are bluish green. I removed them from my camera and I'm going to send
> it to get it's transmission analyzed.
>
> Hope this doesn't hurt you or your wife's ego, but good exposure with IR
> films, especially kodak's, when using the camera's built in meter are the
> result of luck and the wide exposure latitude of the film, NOT because your
> camera can meter infrared light. The camera was designed specifically NOT to
> meter infrared light. I repair cameras/lenses, so I know from first hand
> experiences.
>
> Also given the fact that 99.9% of Infrared photos are taken under relatively
> consistent "sunny 16 type " lighting conditions, you don't even have to be
> that lucky to get a good exposure. Add to this that the most IR photos are
> nature light photos where the amount of IR light is very near/proportional
> to the amount of visible light. In fact it's kind of hard not to get a
> printable negative if you ask me.
>
> And as far as AF is concerned the red filter will shift the focus somewhat
> to compensate for the focus. Thus shooting at f/5.6 and using AF basically
> solves the focus correction issue.
>
> You can try to meter Infrared light through a built in filter that blocks
> it, but its about the worse advice I've ever heard. Better advice would be
> to meter the visible light and assume the IR light will be almost identical
> for natural light, and a little higher for Tungsten light. Telling people
> they can meter infrared light gives them a false sense of security.
>
> Peace, Rolland
>
No egos hurt, here! <G> I wasn't advising metering IR, but just
commenting that, given the circumstances surrounding the taking of the
photos, it seems unnecessary to go through all the machinations
mentioned. Even in the studio. I think a lot of mystique has arisen
around IR usage, and a lot of it is inflated.
I had heard about the IR blocking nature of the meter filters, but
experience made me wonder. My 1n manual says nothing about metering
problems with IR, only focus problems. And if a meter has a problem
with IR, wouldn't a 25 or 29 filter cause problems with metering normal
film? After all, a blue green filter would block most of the
transmission of red light in general, wouldn't it? I'm not trying to be
argumentative, just trying to understand what is going on better.
Skip
--
Shadowcatcher Imagery
http://www.shadowcatcherimagery.com
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