What is type of metering on M6 TTL vs. M6 Classic vs. Leica M5 vs. Leica
CL? I would like to know the differences...
For spot metering, should I point the meter at the shadows of the
object I am interested in? For example, I was shooting a nighttime
gas station and got an underexposed shot. I pointed near one of the
lights but should I pointed the camera at the darker shadows? Which
shadows should I meter off?
-- Bill Bolger (bill.bolger@yale.edu), January 09, 2002
Which shadows to meter? That's a tough question, with the usual "it
depends" answer. ;-)
As with any meter, the trick is to know what it is metering, and what
the meter is telling you. I cant speak to the earlier models, but the
M6 TTL is technically a spot meter, meaning that the drop off from the
metered area to the adjacent non-metered area is very steep. It is,
however, a big spot, and varies somewhat with the lens choice. Getting
to know the area of coverage takes a little practice, but is quite
do-able.
For a night scene, I'd start with metering the bright areas, and make
a mental note of the exposure. Then, meter the middle and dark
shadows, taking note of the differences. Then, you can mentally apply
a bit of (modified) Zone System interpretation. Assuming you want some
detail in the highlight areas (not the lights themselves), your
starting point would be 3 stops wider than the highlight measurement
(placing the highlights at Zone VIII). With that as the exposure to be
set, then determine how much difference there is between that and your
shadow measurements. At night, the mid shadows should be within a
couple of stops of that setting, and the deep shadows will likely be
four or more stops beyond your setting, meaning that the deep shadows
won't have detail. What you actually expose at would be a matter of
how you want to balance between the highlights and the shadows. For
most night scenes, you have to give up detail at one end or the other.
Which end depends on the nature of the scene, and what you want the
image to look like.
Here are a couple of different approaches:
-- Ralph Barker (rbarker@pacbell.net), January 09, 2002.
Bill:
Every basic meter, including the one in an M6, assumes every object
it meters is middle-gray (Zone V) in color and is calibrated to
generate an exposure that delivers that result. In other words, if
you point your meter at something that is neutral gray in color, the
exposure the M6 generates will be correct for the scene. If
alternatively you meter off a dark shadow, say 2 stops lower than
neutral gray (Zone III) you meter will give a reading that reproduces
the shadow as neutral gray and everything else will be too light as
well - so you must reduce your exposure by 2 stops to make your image
look right. Conversely, if you metered off a bright light source, say
3 stops brighter than neutral gray (Zone VIII), your meter will
generate an exposure that renders the light as neutral gray and
everything else darker as well, so you have to add 3 stops of
exposure back in to return the image to its proper values.
The easiest method is to meter directly off of an object that is
middle gray in color. Some objects that meet this criteria are green
grass, clear blue sky, wet concrete, or old bricks. If nothing like
this is available, you need to pick an object of known value and
compensate. For example, wet sand at the beach is Zone VI, so if you
meter off of it, you would have to add back one stop to lighten it
accordingly. Dry sand falls in about Zone VII, so if you metered off
of it, you'd have to add back in 2 stops. Evergreen trees are Zone
IV, so you have to subtract 1 stop if you metered off of one of them.
Black hair of fur is Zone III, so you'd subtract 2 stops if you
metered off of a Labrador retriever.
Ansel Adams has a trio of books that are VERY good references for the
subject of photography, and I suggest every photographer should
consider them essential reference sources. They are called: "The
Camera", "The Negative" and "The Print". The second one deals with
this subject in detail, as do many other books on basic photography
or the Zone system.
The meter in the M6 is essentially a large-area spot meter. The TTL
is identical in pattern, though I believe it is slightly less
sensitive at the low end, but better at the high end. The M5 and CL
had a metering cell on a flag that dropped down into the light path
prior to exposure, and worked in much the same fasion and covered
similar area to that on the M6 and M6TTL. FWIW, the CLE had a multi-
patterned shutter curtain and gave more of a center-weighted pattern
than the others, while the Hexar RF uses a stripe on the shutter
curtain to reflect light to the metering cell.
I hope this helps!
~ Jack
-- Jack Flesher (jbflesher@msn.com), January 10, 2002.
