"correct" exposure

colton.neil

Senior Member
So I have recently found out that my camera has a nifty little line in the view finder that will tell me when my photos are "correctly" exposed. Only problem is that it seems to me that "correct" always looks slightly over exposed, so here is the question. Is there such thing as correct exposure or is this personal preference? And as a secondary questions do experienced photographers pay much attention to the built in exposure meter?

as an example this is what my D750 might say is properly exposed

DSC_1224.jpg


whereas this is what I think is properly exposed

DSC_1225.jpg
 

Fred Kingston

Senior Member
You need to do some homework... There are 3 different light meters in your camera... Or, I should say, there's one light meter, but depending on how you have it set, it measures light in 3 different ways... and each is dependent on where you have the focus point pointed... :)

So, you can determine where in your scene the meter is reading, and additionally, how it reads the light where you are metering...

They're called a spot meter, an area meter (which further depends on the dimensions, and number of spots you select to average, and there's a matrix meter; which averages the over-all area of the scene...

Read about each one, and then do some experiments to see which one suits you... There is no "right" or "only" one... they're mostly dependent on your personal needs.
 

colton.neil

Senior Member
Thanks for the quick reply, and the advice. I'm familiar with the metering modes, is that what is causing my images to appear sort of "washed out", improper metering?
 

Horoscope Fish

Senior Member
The exposure meter in your camera is calibrated to expose to middle grey, not what the eye sees, so darker scenes often get slightly over-exposed, while very bright beach or snow scenes tend to look slightly under-exposed. There's an old adage that says something to the effect of, when it's bright, go brighter; when it's dark go darker. Meaning if the scene is very bright you're going to want to increase exposure to compensate for the fact your meter is going to want to "under expose" and that if the scene is particularly dark, use your exposure compensation to decrease the exposure because the meter is going to want to compensate by "over exposing". It does this because it wants to balance everything to middle grey. This averaging works pretty well but the further away from "average" the scene, the less accurate the metering will appear. It's not, really, it's doing its job just fine, but you're going to have to learn how the meter "thinks" in order to get exposure that matches what you're seeing.

Just remember Middle Grey: The camera's meter *always* wants to expose to middle grey. Always. Always. Always.
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J-see

Senior Member
When metering your cam tries to expose in such a manner the middle tones have a certain brightness. Whether that's the 18% gray or not doesn't matter at the moment. Depending upon how you measure light and the dynamic range of your scene you frame, the cam steers exposure into the direction those middle tones require.

This correct exposure is a remnant of days past and in my opinion no longer necessary but it's what we are stuck with. It's not because the cam considers it correct, we have to agree. That's why we play with metering, compensate exposure or go full manual and do whatever we like. Or we adjust it to our liking in post.

But until they release programmable cams, we're stuck with this standardized exposure.
 
I used to explain it to new camera owners when I would sell them a camera. It you took the world and put it in a blender the final color would be 18% grey. So you have to look at your scene and determine if that is what it would average out to. Pick the metering mode. Spot, center weighted or average (full scene) most of the time I use center weighted and it works pretty good. I know that on some scenes I will need to change the mode or compensate by using the over/under exposure. a quick peek at the first shot in a series lets me know if it is all working or not.

After shooting for a few years this is all quite easy. It is just a matter of thinking about the shot before you shoot.
 

J-see

Senior Member
Easiest is using exposure compensation but that only works in auto-modes. When manual the D750 allows you to check the shot before you shoot when using live-view and enabling exposure preview. You can enable the histogram too.

In auto-modes exposure compensation (+/-) is a handy manner to adjust exposure but it affects other settings depending what mode you are shooting in. It all depends on your scene and what you prefer the shot to be. Some require high-light metering, others do better with matrix. Some you compensate, others are fine without.

You're in control and have to decide what. If not, the cam does.
 

colton.neil

Senior Member
I used to explain it to new camera owners when I would sell them a camera. It you took the world and put it in a blender the final color would be 18% grey. So you have to look at your scene and determine if that is what it would average out to.

Thats a really great example, so my camera is going for a universal average of 18% grey but a scene of only a blue sky with no clouds wouldn't average to 18% grey. I have been using full scene mostly, I will try it with center weighted and see what I get. Thanks for the tip!
 

J-see

Senior Member
You can check what the cam does when you shoot a white paper and another shot of a black paper. When that paper is all that you frame with the cam set to an auto-mode, both shots will be gray.
 

Horoscope Fish

Senior Member
Do you mean to manually adjust exposure compensation via the little +/- button or just use the meter in the viewfinder to go darker or lighter?
In short, yes. Using the Exposure Compensation button is the fastest, easiest way in my opinion and without going into detail about the whole Exposure Triangle.
...
 

Kultfunk

Senior Member
Thats a really great example, so my camera is going for a universal average of 18% grey but a scene of only a blue sky with no clouds wouldn't average to 18% grey. I have been using full scene mostly, I will try it with center weighted and see what I get. Thanks for the tip!

same story i'm afraid... when you meter something 'dark-ish' en the surroundings are not that 'bright' it could get even worse...
matrix metering is not my friend also... most of the time i use spot metering @ my subject, in the example you gave here it's just a matter of dialing in an exposure compensation of (i guess) -0,7 or -1 and it's done !
 

richarddacat

Senior Member
Awesome answers.

I recently saw a video on this very subject by Mike Browne.
Much like the answers here his are well explained with visual examples and he's quite a hoot to watch and listen.
Seeing and reading the subject material more than once always helps me understand.
 

Danno

Senior Member
These explanations are very helpful. Being new to photography I struggled with the same issue. I had moved to center weighted and single point metering, but still struggled. This really helped.
 

Felisek

Senior Member
Just remember Middle Grey: The camera's meter *always* wants to expose to middle grey. Always. Always. Always.
,,,,

Not always.

This is only true in centre-weighted and spot meting, but not in matrix metering. Below is a quote from Nikon website. As far as I understand it, they apply a machine learning algorithm (probably a neural network) trained on 30,000 real images to guess the correct exposure for the given scene. It will depend on the spatial distribution of light and colour. It is much more complicated than averaging to middle grey.

By the way, the Nikon's statement about "accessing a database of 30,000 actual images" is misleading. There are no 30,000 images stored in your camera, only a neural net trained on them.

The 3D Color Matrix Meter II takes into account the scene's contrast and brightness, the subject's distance (via a D- or G-type NIKKOR lens), the color of the subject within the scene and RGB color values in every section of the scene. 3D Color Matrix Metering II also uses special exposure-evaluation algorithms, optimized for digital imaging, that detect highlight areas. The meter then accesses a database of over 30,000 actual images to determine the best exposure for the scene. Once the camera receives the scene data, its powerful microcomputer and the database work together to provide the finest automatic exposure control available.
 

Woodyg3

Senior Member
Contributor
Matrix metering gives excellent results in a large percentage of situations. It is still nowhere nearly as intelligent as the person behind the camera. (We hope.)
 

J-see

Senior Member
I mostly meter depending upon light in my scene. When I shoot scenes that have plenty of bright skies, I find it handier to switch to highlight metering and compensate that to the right. Matrix I find handier when it gets darker.

Spot and center I use less these days but when it gets warm enough to macro or bird, they have their use.

But no matter how I meter, I pay most attention to my histogram since clipping has to be avoided or minimized.
 
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Horoscope Fish

Senior Member
Not always.

This is only true in centre-weighted and spot meting, but not in matrix metering. Below is a quote from Nikon website. As far as I understand it, they apply a machine learning algorithm (probably a neural network) trained on 30,000 real images to guess the correct exposure for the given scene. It will depend on the spatial distribution of light and colour. It is much more complicated than averaging to middle grey.

By the way, the Nikon's statement about "accessing a database of 30,000 actual images" is misleading. There are no 30,000 images stored in your camera, only a neural net trained on them.
And in a perfect world that technology probably works really, really well and as I recall it's a moot point if you don't have a Nikon D or G variant lens on your camera, which I *very* frequently do not. Even then, in my experience, Matrix metering is commonly quite off the beam with it's exposure calculation. Falling back on the "middle grey" line of thinking has explained why my photo's were not matching what I was seeing with the naked eye was what allowed do to compensate accordingly. And really that is what I think is important here: The concept of the meter exposing for middle grey needs to be understood so it can be compensated for because it WILL happen, even when using Matrix metering, and even with a G or D variant lens.

Many new photographers get confused why the meter is not exposing such that the photo matches what they are seeing with the naked eye. The reason is the meter, generally speaking, exposes for middle grey.
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