On camera vs off camera metering

digiconvert · Oct 29, 2008

Finishing a roll of film the other day I thought I'd check on camera metering (reflected) vs my Minolta III with the diffuser cone on a distant subject. The results are attached. The left hand image is from the camera metering. I must admit to being amazed at how under exposed the Cathedral is on the camera metered shot , the EOS 30 is usually pretty good.
For info both are neg scans from Portra 160NC and the only PS work is to set the white point on both using the edge of one of the clouds and mid grey on a roof I know to be about the right tone plus a little unsharp mask.

Comments more than welcome.

Akki14 · Oct 29, 2008

Looks like your camera was metering the sky and you did incidence metering which is suppose to be more accurate and less likely to be fooled in these situations.

digiconvert · Oct 29, 2008

Yes but it reinforces the need for meters even in this digi world.

Excalibur2 · Oct 29, 2008

digiconvert said:
Finishing a roll of film the other day I thought I'd check on camera metering (reflected) vs my Minolta III with the diffuser cone on a distant subject. The results are attached. The left hand image is from the camera metering. I must admit to being amazed at how under exposed the Cathedral is on the camera metered shot , the EOS 30 is usually pretty good.
For info both are neg scans from Portra 160NC and the only PS work is to set the white point on both using the edge of one of the clouds and mid grey on a roof I know to be about the right tone plus a little unsharp mask.

Comments more than welcome.

Yep agree with the other guy, the white sky fooled the camera (blue sky less)......my Konica TC has a good idea with tricky light situations (well it was an original idea about 30 years ago)..........half press the shutter button down and point the camera at some grass or anything light grey (equivalent to incident or roughly kodak grey card)........ it's called exposure "Memory" lock.......it will hold that exposure after re-composing and finally pressing the shutter button all the way to take the shot with the correct exposure.

In the past I used to point the exposure meter (weston) at the back of my sun tanned hand or again grass or grey pavement, and set the camera to those readings.

haris · Oct 29, 2008

Take any handheld (off camera) meter in reflected metering position, aim it toward any normally bright object and include in scene lots of backlighting (or sky as in your example) and it will give same underexposed result. It is not that your on camera meter is bad, it is lots if backlighting which fools any meter.

eddym · Oct 30, 2008

So where did you meter? This looks more like operator error than meter error to me. Always remember two things:
The camera has no idea what you are taking a picture of;
and every meter thinks the world is gray.

Chan Tran · Oct 30, 2008

digiconvert said:
Yes but it reinforces the need for meters even in this digi world.

Nah! in the digi world you just guess the exposure then check your result on the LCD, make adjustment then shoot again. I don't use either the built in nor hand held meter with my digital camera and I always shoot in manual mode. I get to the point where my first guess is generall quite good. I know the respond of my little digi cam well enough that I use it as the meter for my film camera. Well I gota shoot film or else I am not supposed to be here right?

Ed Sukach · Oct 31, 2008

Apparently, the metering was influenced by the "Angle of Acceptance". The in-camera meter "read" the amount of light received (reflected) from the entire frame, and responded with an "average" value, including a lot of light from the sky.
The Minolta III (I'm NOT familiar with this meter) read a smaller portion of the frame (center) and was less influenced by the light from the sky.

One question (see "not familiar" preceding) ... Is the operation of this meter with the "diffuser cone" the proper way to go for
reflected metering? Diffusers (usually spherical) are proper in incident metering.

Lee L · Oct 31, 2008

Ed Sukach said:
The Minolta III (I'm NOT familiar with this meter) read a smaller portion of the frame (center) and was less influenced by the light from the sky.

The Minolta Autometer III is an incident meter. The diffuser would be more properly described as a dome, or hemisphere, typical of incident meters.

Lee

Ed Sukach · Oct 31, 2008

Lee L said:
The Minolta Autometer III is an incident meter. The diffuser would be more properly described as a dome, or hemisphere, typical of incident meters.

If that is the case, the amount of light reflected from the scene may easily be different from the light reaching the meter from another source (incident).
Incident metering is taken AT the subject; reflective metering, AT the camera.

Reflective metering is affected by the nature of the subject (dark will send less light to the meter than light); incident is not - measuring the amount of light falling on the subject.

I would use nothing other than "incident" in studio work (give me a 2% 'worm-out' window here). In landscape work, it would be very difficult to take a meter reading AT the subject, and travel to the camera without having the amount of light falling on the subject (scene) change.
i

2F/2F · Oct 31, 2008

You have illustrated an extremely basic point. Any beginning photography student who listens to the instructor and reads the text knows that the left photo is what happens when you listen to a reflected meter in such a situation, and that the right photo is what happens when you listen to an incident meter. One of the very first things a good instructor teaches beyond the basics is how to use a meter; how to convert what your meter is telling you into a "good" exposure using your meter's provided info and your brain. Reflected meters are inherently flawed for metering an entire composition at once and going with exactly what the meter sez. We all know this. It has nothing to do with film or digital. It has to do with knowing how to use a meter.

SilverGlow · Oct 31, 2008

digiconvert said:
Yes but it reinforces the need for meters even in this digi world.

I strongly disagree. For digital nothing beats spot metering AND histogram reading. Even matrix/evaluative metering most DSLR's are very good, and again all one needs is the skill in reading a histogram.

Now when I shoot film I use a handheld light meter, but never for digital.

SilverGlow · Oct 31, 2008

Chan Tran said:
Nah! in the digi world you just guess the exposure then check your result on the LCD, make adjustment then shoot again. I don't use either the built in nor hand held meter with my digital camera and I always shoot in manual mode. I get to the point where my first guess is generall quite good. I know the respond of my little digi cam well enough that I use it as the meter for my film camera. Well I gota shoot film or else I am not supposed to be here right?

Perhaps the worse way to meter in digital is to rely on the LCD image of the shot you just took. That LCD screen lies! It is forever at the mercy of ambiant light, and the brightness setting of the screen, and the angle of view of the shooter too.

A far better way to judge exposure with digital is to rely on the histogram. With most DSLR's matrix/evaluative metering works very well, and even for backlit subjects too.

Leave the handheld meters to the studio shooters, and film shooters...for everything else digital, the camera's built in light meter is great but only if used in conjuction with the histogram.

Sirius Glass · Oct 31, 2008

Excalibur2 said:
Yep agree with the other guy, the white sky fooled the camera (blue sky less)......my Konica TC has a good idea with tricky light situations (well it was an original idea about 30 years ago)..........half press the shutter button down and point the camera at some grass or anything light grey (equivalent to incident or roughly kodak grey card)........ it's called exposure "Memory" lock.......it will hold that exposure after re-composing and finally pressing the shutter button all the way to take the shot with the correct exposure.

In the past I used to point the exposure meter (weston) at the back of my sun tanned hand or again grass or grey pavement, and set the camera to those readings.

I always take the TTL reading of the object or area that I would want to be neutral gray if I were shooting black and white. I do this for both color and black and white [hey, black and white are colors too!] whether I am using my Nikon (35mm) or my Hasselblad (MF).

Steve

wiltw · Oct 31, 2008

SilverGlow said:
I strongly disagree. For digital nothing beats spot metering AND histogram reading. Even matrix/evaluative metering most DSLR's are very good, and again all one needs is the skill in reading a histogram.

And I disagree about the utility of the histogram...if you had a scene with shadowy area under the trees, some of the scene is the building, and some of the scene is sky, the histogram tells you nothing about the pixels specifically which make up the building! You know the quantity of dark, medium and light pixels, whether too many of them seem to be falling off the histogram, but nothing about the suitability of the pixels that are rendering the main object of interest (whatever that might be!)

But this is an analog forum, so the debate about histogram is pointless!

Excalibur2 · Oct 31, 2008

....and a nice bue sky is sorta grey to a light meter (so wont fool it so much)............so all the holiday pics in sunny Spain come out and white sky UK pics have problems.

eddym · Oct 31, 2008

Sirius Glass said:
I always take the TTL reading of the object or area that I would want to be neutral gray if I were shooting black and white. I do this for both color and black and white [hey, black and white are colors too!] whether I am using my Nikon (35mm) or my Hasselblad (MF).

Steve

Steve, you know how to meter a scene. Most people don't, and they call the result, "fooling the meter." Meters aren't fooled; photographers are fooled.

Excalibur2 · Oct 31, 2008

eddym said:
Steve, you know how to meter a scene. Most people don't, and they call the result, "fooling the meter." Meters aren't fooled; photographers are fooled.

..If meters weren't fooled then they could read bright white and coal seller black for correct exposure...............in theory you can't trust a meter that is calibrated to appx Kodak grey, unless all of the subject is appx Kodak grey......what happens in practice is the exposure latitude of the film covers objects that are moving to white or black.

Sirius Glass · Oct 31, 2008

eddym said:
Steve, you know how to meter a scene. Most people don't, and they call the result, "fooling the meter." Meters aren't fooled; photographers are fooled.

For the record: I have met light meters that I did not like!

Steve

benjiboy · Oct 31, 2008

Sirius Glass said:
For the record: I have met light meters that I did not like!

Steve

I've met some I really like , but I wouldn't let my sister marry one !

removed account4 · Oct 31, 2008

Ed Sukach said:
If that is the case, the amount of light reflected from the scene may easily be different from the light reaching the meter from another source (incident).
Incident metering is taken AT the subject; reflective metering, AT the camera.

Reflective metering is affected by the nature of the subject (dark will send less light to the meter than light); incident is not - measuring the amount of light falling on the subject.

I would use nothing other than "incident" in studio work (give me a 2% 'worm-out' window here). In landscape work, it would be very difficult to take a meter reading AT the subject, and travel to the camera without having the amount of light falling on the subject (scene) change.
i

hey ed!

great to see your posts

SilverGlow · Nov 1, 2008

wiltw said:
And I disagree about the utility of the histogram...if you had a scene with shadowy area under the trees, some of the scene is the building, and some of the scene is sky, the histogram tells you nothing about the pixels specifically which make up the building! You know the quantity of dark, medium and light pixels, whether too many of them seem to be falling off the histogram, but nothing about the suitability of the pixels that are rendering the main object of interest (whatever that might be!)

But this is an analog forum, so the debate about histogram is pointless!

The particular questions you ask of the histogram are irrelevent because you want to transpose the functionality of a meter to the histogram, and it's apples and oranges. You want to know where the leaves or Sally's face are on the histogram, and well, there are far better questions to ask of a histogram, frankly.

When you look at the histogram, the far left are the darkest part of your composition (for example the patch of dirt your cute wife is posing on), and the highlights on the far right are (for example the patches of over cast skys in your composition). That is really all you need to know because everything in the middle often can safely be shifted up or down via EC. It's the extreme left (shadows) and extreme right (highlights) that could get sacrificed.

So don't try to use a light meter in the same way you might read a histogram, and once you figure this out, you too will find that the histogram gives better "advice" then a light meter.

Another way to look at this is that a light meter will tell you a reading based on what you decide is 18% gray, and that is it. The histogram shows the amount of distribution at 18% (middle) and for the entire dynamic range..far more helpful to a digital photographer.

I've yet to come across a composition that could not be exposed correctly without a hand held meter.

On the other hand, i readly see the value of a handheld meter for shooting film, and for this reason I use one from time to time but only when I shoot film.

eddym · Nov 1, 2008

Excalibur2 said:
..If meters weren't fooled then they could read bright white and coal seller black for correct exposure...............in theory you can't trust a meter that is calibrated to appx Kodak grey, unless all of the subject is appx Kodak grey......what happens in practice is the exposure latitude of the film covers objects that are moving to white or black.

That's like saying that a yardstick fools you because it does not measure in meters. Any tool is only as good as the brain of the user.

Excalibur2 · Nov 1, 2008

eddym said:
That's like saying that a yardstick fools you because it does not measure in meters. Any tool is only as good as the brain of the user.

erm so your examples would be for most similar things............ "if only" or "just needs a bit of intelligence to adapt" and so on................

The point is:- a film camera exposure meter cannot give the correct exposure reading for white or black.. so that's that.....whether you think average Joe public should know/known this fact is another argument.

eddym · Nov 1, 2008

Excalibur2 said:
The point is:- a film camera exposure meter cannot give the correct exposure reading for white or black.. so that's that.....whether you think average Joe public should know/known this fact is another argument.

I thought we were all photographers. Average Joe public takes pictures these days with his cell phone.

On camera vs off camera metering

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