metering question

hi,

i have a question regarding a metering situation. i have both a view camera,
and a rangefinder 6x7, so it would apply to both. if i am using a stack
(really on or two) cokin-type filters, and need to get an accurate meter,
acn i just use my minolta FM IV with the flat diffused head and aim it
through the filters?

it makes sense to me, but if that's completely wrong, let me know why....

thanks

G- Blank" wrote in message
...

Depends on the filters being used and the spectral sensitivity of
the meter. Just as some filters can be filtered through using a
cameras internal meter system the same applies to the hand held meter.

The success of this practice is also dependent on the type of film and
the scene contrast and how the said filters effect it (that is if your
hoping for a general- one measurement type scenario.)

Why don't you just say that you don't know.

In article ,
"joe mama" wrote:

hi,

i have a question regarding a metering situation. i have both a view camera,
and a rangefinder 6x7, so it would apply to both. if i am using a stack
(really on or two) cokin-type filters, and need to get an accurate meter,
acn i just use my minolta FM IV with the flat diffused head and aim it
through the filters?

it makes sense to me, but if that's completely wrong, let me know why....

thanks

Depends on the filters being used and the spectral sensitivity of
the meter. Just as some filters can be filtered through using a
cameras internal meter system the same applies to the hand held meter.

The success of this practice is also dependent on the type of film and
the scene contrast and how the said filters effect it (that is if your
hoping for a general- one measurement type scenario.)

In the simplest terms the answer is yes you can do it, however there
will be situations that require you to test and learn from the results.


--
"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

greg_____photo(dot)com

In article ,
"Just Me" wrote:

G- Blank" wrote in message
...

Depends on the filters being used and the spectral sensitivity of
the meter. Just as some filters can be filtered through using a
cameras internal meter system the same applies to the hand held meter.

The success of this practice is also dependent on the type of film and
the scene contrast and how the said filters effect it (that is if your
hoping for a general- one measurement type scenario.)

Why don't you just say that you don't know.

Because then I would have to say my name was John Stafford.

--
"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

greg_____photo(dot)com

"Just Me" wrote in message
...

Why don't you just say that you don't know.


Thus speaks Mr. Snark. Nothing useful to offer,
but insults and jabs are given freely and generously.


rafe b
www.terrapinphoto.com

rafe b spake thus:

"Just Me" wrote in message
...

Why don't you just say that you don't know.

Thus speaks Mr. Snark. Nothing useful to offer,
but insults and jabs are given freely and generously.

Man has a point, though. Think about all those poor electrons being
needlessly tortured.

(btw, I like "snark": good choice of words.)


--
The only reason corrupt Republicans rule the roost in Washington
is because the corrupt Democrats can't muster any viable opposition.

i have a question regarding a metering situation. i have both a view
camera,
and a rangefinder 6x7, so it would apply to both. if i am using a stack
(really on or two) cokin-type filters, and need to get an accurate meter,
acn i just use my minolta FM IV with the flat diffused head and aim it
through the filters?

it makes sense to me, but if that's completely wrong, let me know why....


should work, as for variations in meter sensitivity vs film, well if you are
shooting transparencies with very critical requirements, that's what
polaroid backs were invented for.

remember that filters come with a filter factor, that's to help you factor
that in your exposure. a filter factor of 2x means that the expo is
doubled, or one stop. you can stack your exposure factors like you stack
your filters, of course it gets back to guess work when you use graduated
filters and vignettes. But at least with filter factors you can dial that
in on your meter instead of screwing the filters on and off your camera,
even those slide in filters can be annoying to constantly pulling them in
and out, (as in move the camera over a bit and ruin your composition.

This reply is echoed to the z-prophoto mailing list at yahoogroups.com

joe mama wrote:

hi,

i have a question regarding a metering situation. i have both a view camera,
and a rangefinder 6x7, so it would apply to both. if i am using a stack
(really on or two) cokin-type filters, and need to get an accurate meter,
acn i just use my minolta FM IV with the flat diffused head and aim it
through the filters?

it makes sense to me, but if that's completely wrong, let me know why....

thanks

cokin filters are not standard filters. Don't
use them myself (garish color) so consult Cokin
I'd say for filter factors. But in general I
would say yes in practice given panchromotic film...

Best to 1) not stack any filter and 2) if in
doubt bracket.

David Nebenzahl wrote:

rafe b spake thus:

"Just Me" wrote in message
...

Why don't you just say that you don't know.

Thus speaks Mr. Snark. Nothing useful to offer,
but insults and jabs are given freely and generously.

Man has a point, though. Think about all those poor electrons being
needlessly tortured.

(btw, I like "snark": good choice of words.)

Yeah. It applies readily to you, so I understand
your fondness for it, chicken breath...

"joe mama" wrote in message
t...
hi,

i have a question regarding a metering situation. i have
both a view camera, and a rangefinder 6x7, so it would
apply to both. if i am using a stack (really on or two)
cokin-type filters, and need to get an accurate meter, acn
i just use my minolta FM IV with the flat diffused head
and aim it through the filters?

it makes sense to me, but if that's completely wrong, let
me know why....

thanks
As Gregory Blank posted it will depend on the meter. If
the meter approximates the spectral sensitivity of the film
the results will be reasonably close. I just checked four
black and white contrast filters on two meters of different
types. The filters were a Wratten A (No.25) Medium Red, a
Wratten X-1 (No.11) Medium Green, a Wratten G (No.15) dark
yellow, and a Wratten K-2 (No.8) Light Yellow. These filters
are old but appear to be unfaded.

The official filter factors for these filters a
A, 8 times
X-1, 4 times
G, 3 times
K-2, 2 times

The meters were a Sekonic Studio Deluxe (Selenium) and a
Gossen Luna Pro (CdS). These were chosen because the two
types of sensors have rather different spectral
sensitivities and are typical of many meters on the market.
All readings were reflected light. The Sekonic was used
with the "grid" attachment, the Gossen Luna Pro with the
hemisphere slide to the side.

I used two test targets. One was a white card (the back
of a Kodak 18% Gray card), the other an actual scene, namely
the houses across the street, a typical scene including all
sorts of colors and some sky.
Results.
In no case did either of the meters indicate the
published filter factor. The closest was the Sekonic on the
Red filter, which indicated close to 8 times but not exactly
and the reading also varied somewhat with the exact choice
of scene.
In general, both meters indicated substantially less
exposure increase than the filter factors give.

Another test, but not a delibrate one, was done yesterday
when I did some outdoor photography using a Nikon equivalent
to a K-2, on my Nikon F using the internal TTL exposure
meter. The film used was Kodak 100T-Max. The exposures are
somewhat more dense than those made without the filter. No
change was made to the ISO setting. It is possible the
differences in exposure may have been due to subject matter
or my setting of the exposure. I was not testing for the
metering so was not careful about this. The increased
exposure suggests that the internal sensor was more effected
by the filter than the film was. I have not tested this on
the bases of the f/stops yet, I simply did not notice them
at the time.

Discussion.
Without actual exposure tests not much can be made of the
above. Filter factors are determined on the basis of some
assumed "average" spectral content of the scene and may not
be correct for some scenes. As Gregory posted, there is also
a difference between the spectral sensivity of the meter and
the film. Unless they match there is likely to be an error.
I can't go beyond this without actual photographic tests.
If the person (?) who asked why Gregory couldn't just say he
didn't know wants to say the same of me, go right ahead,
there is some justification of it. However, I've tried to
provide some experimental data.
I think the answer is going to be, as it often is, to
test. If you make tests and find that metering through the
filters gives you satisfactory results then you're home
free:-)


--
---
Richard Knoppow
Los Angeles, CA, USA