reflected light vs incident light metering

sreenath wrote:

Hi All,

I was reading Kodak Color handbook (a very old collection of booklets
from Kodak, possibly late 60's), where there is a long treatment of
various techniques.

There is a statement in that book that surprised me:

"Field studies have shown that pictures made using reflected metering
appear to be more pleasant than those made with incident light
metering"

I may not be repeating exact words, but this is the idea.

How is it that pictures made using reflected light metering are "more
pleasant"?

Considering that it was an old book, the views at that time may have
been very different. Hand held light meters are much better now than
they were in the distant past. A modern comparison of Incident .vs.
Reflected metering is at:

http://www.sekonic.com/BenefitsOfIncident.html The images show the
comparison nicely.

Ciao!

Gordon Moat
A G Studio
http://www.allgstudio.com
http://www.agstudiopro.com Coming Soon!

"sreenath" wrote in message
om...
Hi All,

I was reading Kodak Color handbook (a very old collection of booklets
from Kodak, possibly late 60's), where there is a long treatment of
various techniques.

There is a statement in that book that surprised me:

"Field studies have shown that pictures made using reflected metering
appear to be more pleasant than those made with incident light
metering"

I may not be repeating exact words, but this is the idea.

How is it that pictures made using reflected light metering are "more
pleasant"?

Thanks,
Sreenath

It doesn't surprise me in the least (let the flames begin). If you think
about it, incident metering makes little
sense in either vision or photography (another cue for dissenting opinions).
What gives an object color, shape, and texture is the light that it REFLECTS
back to your eye or your film/digital sensor. Take this to the extreme, and
consider that you want to photograph a black hole (so dense, even light
doesn't escape...remember that light behave both like a particle and a
wave)...it REALLY DOESN'T matter how much light falls on it, none is coming
back so it just appears to be a black area with no shape, color, or texture.
I'm sorry, but the human eye and photographic processes ARE NOT sensitive to
how much light FALLS on an object, only on how much comes back to the sensor
(eye, digital sensor, film, etc.).

So, careful (so as not to be deceived by a non-representative area)
reflected metering yields results more like what you see and attracted you
to the subject in the first place. Incident metering can yield results
unlike what you are seeing so if the scene is unremarkable, you might prefer
those results.

[INSERT OPPOSING VIEWS HERE]

George wrote:



I'm sorry, but the human eye and photographic processes ARE NOT sensitive to
how much light FALLS on an object, only on how much comes back to the sensor
(eye, digital sensor, film, etc.).

You're correct that a sensor can only detect what is being thrown
at it; however for a given scene if a given amount of light falls
on it, an incident reading of that light indicates what will be
detected by the recording sensor (at that setting). Some objects
may reflect an amount of light that falls below (or above) the
latitude of the sensor, and they will be unrecorded or burned
out... but that's an issue with film (sensor) not the meter.


So, careful (so as not to be deceived by a non-representative area)

That is a very good reason to use incident. It cannot be
deceived by the non-representative subject or metering object.

reflected metering yields results more like what you see and attracted you
to the subject in the first place. Incident metering can yield results
unlike what you are seeing so if the scene is unremarkable, you might prefer
those results.


The meter in the camera (exception: Nikon F5, D70 RGB metering,
not sure about D100 and the D2/D1x, ) is calibrated for white
light reflecting off of an 18% grey surface. Hence, what you
point the meter at is affecting the accuracy of the reading. You
can always bring along a grey card but that is no less
inconvenient than an incident meter.

The popularity of reflected metering (in-camera) is mainly due to
convenience (and possibly cost)... It is always more convenient
to meter through the viewfinder, and reduces the equipment count
and load. However, there aren't always representative objects to
meter which means some judgement is required to get the desired
effect...

Both are of course useful ways to meter, if well understood, but
the most consistent results come from incident metering, not
in-camera spot or weighted metering. An exception here is if
using the in-camera meter to make a measurement and determine the
correct setting, that that setting (or reciprocals of it) be used
in manual mode for all subsequent shots in the same lighting and
close to same orientation.

Cheers,
Alan.

--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

"Alan Browne" wrote in message
...
George wrote:



I'm sorry, but the human eye and photographic processes ARE NOT
sensitive to
how much light FALLS on an object, only on how much comes back to the
sensor
(eye, digital sensor, film, etc.).

You're correct that a sensor can only detect what is being thrown
at it; however for a given scene if a given amount of light falls
on it, an incident reading of that light indicates what will be
detected by the recording sensor (at that setting). Some objects
may reflect an amount of light that falls below (or above) the
latitude of the sensor, and they will be unrecorded or burned
out... but that's an issue with film (sensor) not the meter.


Incident metering wouldn't detect the light that will be detected by the
recording sensor UNLESS
the recording sensor is located at the subject pointed toward the camera
position. Correct? And
locating your camera at the subject and pointing away from it would be quite
a different picture.


Cheers,
Alan.

--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

George wrote:

You're correct that a sensor can only detect what is being thrown
at it; however for a given scene if a given amount of light falls
on it, an incident reading of that light indicates what will be
detected by the recording sensor (at that setting). Some objects
may reflect an amount of light that falls below (or above) the
latitude of the sensor, and they will be unrecorded or burned
out... but that's an issue with film (sensor) not the meter.


Incident metering wouldn't detect the light that will be detected by the
recording sensor UNLESS
the recording sensor is located at the subject pointed toward the camera
position. Correct? And

Not sure what you're getting at, but perhaps my writing above is
not clear.

The incident meter sensor is used at the subject position (or at
least in the same field of light, eg, if the subject is on the
far side of the park, then measure where you are if in the same
light (account for local reflections too) pointing the dome at
the camera).

The in-camera sensor reads the light reflected as if it were off
of a standard reflector (18% grey card) from the subject postion
(or at least whatever is being metered). So if your subject
across the field is big enough and 18% ish grey enough, you'll
get a good reading. Otherwise you need to compensate for the
non-18%-grey of the in camera meter.

This compensation is simply not needed with an incident metering
of the light field. In the simplest use, just point the meter
dome at the camera and that reading will be correct.

locating your camera at the subject and pointing away from it would be quite
a different picture.

Yes, becasue the purpose of the in camera meter is "reflected"
metering, and the purpose of the incident meter is (funilly
enough) incident light metering.

Put a clean, white styrofoam coffee cup over the lens from the
subject position and point it at the camera position. That
reading will be correct... the cup acts similarly to the white
dome on an incident meter. Try that v. a grey card reading and
you will be quite close (1/2 stop or less).

Cheers,
Alan.

--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

sreenath wrote:

Hello,
I am the original poster of this message. I have with me the book and
here are the actual sentences stated in the book.


"Although good results can be obtained with incident-light
measurements outdoors, it is questionable whether the results are any
better than those obtained with reflected-light measurements in
equally experienced hands"

This last para seems to be in the marketese of the time: note
the "in equally experienced hands." statement.

------
Perhaps this better qualifies the statement contained in the original
post.

Yes. It was BS then, and it is BS now. (That's not a reflection
on you, but on Kodak or whoever really wrote it.)

Reflected metering systems (in camera) have gone through a lot of
changes since the text was written (late 60's you say), for the
better ... and yet are still not as reliable as a properly taken
incident reading....unless all your subjects happen to be 18% grey.

Cheers,
Alan

--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

"Alan Browne" wrote in message
...
George wrote:



I'm sorry, but the human eye and photographic processes ARE NOT
sensitive to
how much light FALLS on an object, only on how much comes back to the
sensor
(eye, digital sensor, film, etc.).

You're correct that a sensor can only detect what is being thrown
at it; however for a given scene if a given amount of light falls
on it, an incident reading of that light indicates what will be
detected by the recording sensor (at that setting). Some objects
may reflect an amount of light that falls below (or above) the
latitude of the sensor, and they will be unrecorded or burned
out... but that's an issue with film (sensor) not the meter.


Incident metering wouldn't detect the light that will be detected by the
recording sensor UNLESS
the recording sensor is located at the subject pointed toward the camera
position. Correct? And
locating your camera at the subject and pointing away from it would be quite
a different picture.


Cheers,
Alan.

--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

George wrote:
"sreenath" wrote in message
om...
Hi All,

I was reading Kodak Color handbook (a very old collection of booklets
from Kodak, possibly late 60's), where there is a long treatment of
various techniques.

There is a statement in that book that surprised me:

"Field studies have shown that pictures made using reflected metering
appear to be more pleasant than those made with incident light
metering"

I may not be repeating exact words, but this is the idea.

How is it that pictures made using reflected light metering are "more
pleasant"?

Thanks,
Sreenath

It doesn't surprise me in the least (let the flames begin). If you
think about it, incident metering makes little
sense in either vision or photography (another cue for dissenting
opinions). What gives an object color, shape, and texture is the
light that it REFLECTS back to your eye or your film/digital sensor.
Take this to the extreme, and consider that you want to photograph a
black hole (so dense, even light doesn't escape...remember that light
behave both like a particle and a wave)...it REALLY DOESN'T matter
how much light falls on it, none is coming back so it just appears to
be a black area with no shape, color, or texture. I'm sorry, but the
human eye and photographic processes ARE NOT sensitive to how much
light FALLS on an object, only on how much comes back to the sensor
(eye, digital sensor, film, etc.).

So, careful (so as not to be deceived by a non-representative area)
reflected metering yields results more like what you see and
attracted you to the subject in the first place. Incident metering
can yield results unlike what you are seeing so if the scene is
unremarkable, you might prefer those results.

[INSERT OPPOSING VIEWS HERE]

In theory, incident metering eliminates the problem of how to photograph
snow, or grass or shadow etc. Your meter will never be off because of the
subject and each part of the subject will be recorded on the film in at the
expected density.

The theory sort of falls apart due to the limits of the film. It can't
always record all light levels.

Reflective averaging makes sure the average density of the subject is
grey, which is usually right, but not always.

Now if you use the zone system you get around this, and can use it to
your creative advantage, if you have the skill and time.

In the real world, there is no best, only what works.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math

George wrote-
Take this to the extreme, and
consider that you want to photograph a black hole (so dense, even light
doesn't escape...

OK, let's consider it. If an EV of 8 falls on the subject, an incident meter
would call for some combination of exposure equivalent to f2.0 at 1/60. A
reflected light meter would call for the maximum exposure possible. In both
cases the photo would record the maximum black that the medium allows.
Now if we were to photograph a pair of black slacks, rather than a black hole,
things would be quite different, as well as much easier. Under the same
lighting conditions as above, the incident meter would still call for the same
exposure, and the pants would be rendered as black. A reflected light meter
would, however, call for a much higher setting, rendering the pants
overexposed.




--
Eschew obfuscation!

George wrote:
"sreenath" wrote in message
om...
Hi All,

I was reading Kodak Color handbook (a very old collection of booklets
from Kodak, possibly late 60's), where there is a long treatment of
various techniques.

There is a statement in that book that surprised me:

"Field studies have shown that pictures made using reflected metering
appear to be more pleasant than those made with incident light
metering"

I may not be repeating exact words, but this is the idea.

How is it that pictures made using reflected light metering are "more
pleasant"?

Thanks,
Sreenath

It doesn't surprise me in the least (let the flames begin). If you
think about it, incident metering makes little
sense in either vision or photography (another cue for dissenting
opinions). What gives an object color, shape, and texture is the
light that it REFLECTS back to your eye or your film/digital sensor.
Take this to the extreme, and consider that you want to photograph a
black hole (so dense, even light doesn't escape...remember that light
behave both like a particle and a wave)...it REALLY DOESN'T matter
how much light falls on it, none is coming back so it just appears to
be a black area with no shape, color, or texture. I'm sorry, but the
human eye and photographic processes ARE NOT sensitive to how much
light FALLS on an object, only on how much comes back to the sensor
(eye, digital sensor, film, etc.).

So, careful (so as not to be deceived by a non-representative area)
reflected metering yields results more like what you see and
attracted you to the subject in the first place. Incident metering
can yield results unlike what you are seeing so if the scene is
unremarkable, you might prefer those results.

[INSERT OPPOSING VIEWS HERE]

In theory, incident metering eliminates the problem of how to photograph
snow, or grass or shadow etc. Your meter will never be off because of the
subject and each part of the subject will be recorded on the film in at the
expected density.

The theory sort of falls apart due to the limits of the film. It can't
always record all light levels.

Reflective averaging makes sure the average density of the subject is
grey, which is usually right, but not always.

Now if you use the zone system you get around this, and can use it to
your creative advantage, if you have the skill and time.

In the real world, there is no best, only what works.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math