# Why higher end camera underexposes images?



## duydaniel (Sep 16, 2013)

Hey folks

I have done some homework with high ends CaNikon cameras.
And I found that higher end cameras often "under expose" their images.

If you google "D4 under exposure" or "1Dx under exposure", you will find that quite a bit.
Someone even commented


> I was told by NPS (Nikon Pro Service) that this is by design. All “pro” cameras of the Nikon lineup underexpose by -1/3EV.


src: http://www.luminescentphoto.com/blog/2012/03/29/testing-the-nikon-d4-metering-comparison-with-d700/

I understand that people have different tastes on how they would adjust exposures differently. There is theory about ETTR etc. However, it is interesting to see manufactures set exposure to the left on their professional line up of cameras.

Any thoughts?


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## neuroanatomist (Sep 16, 2013)

Well, what is 'underexpose'? We could also say that non-pro cameras tend to _over_expose, much in the same way that in-camera jpgs tend to be fairly saturated and contrasty, because 'most people' (whoever they are) then to prefer bright, colorful images (same reason most computer monitors are saturated and contrasty at the default calibration, and a proper color calibration with a spectrophotometer tends to make them what some would call 'dull').

Why the exposure difference? Perhaps for highlight preservation - you can lift shadows, but can't recover truly blown highlights. However, it's worth noting that on the Canon 1-series bodies you can adjust the set point of the metering with AE Microadjustment, up to a full stop darker or lighter in 1/8-stop increments (and I suspect Nikon pro bodies have a similar feature, but I don't know for sure).


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## Mt Spokane Photography (Sep 16, 2013)

Many people use the AFMA feature in their Canon or the Fine tuning Feature in their Nikon bodies.

The manual warns you that use of the feature will affect the exposure and that you should use EC to correct it. I suspect that some never read their manual   

I read the manual, but my brain read AF Microadjustment where the manual was talking AE Microadjustment.

As a result, my post was nonsense.


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## neuroanatomist (Sep 16, 2013)

Mt Spokane Photography said:


> Many people use the AFMA feature in their Canon or the Fine tuning Feature in their Nikon bodies.
> 
> The manual warns you that use of the feature will affect the exposure and that you should use EC to correct it. I suspect that some never read their manual



Where does it say that? I don't see anything to that effect in the 7D, 5DII, 5DIII, 1D IV or 1D X manuals, at least not in the AFMA sections.


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## duydaniel (Sep 16, 2013)

Well, I am more interested in knowing their reasoning behind this as Dr John said.
Probably highlight preservation is what the manufactures want to set their pro/consumer lines apart.

Or maybe -1/3 EV make the photo more attractive?
So what is the deal with shooters who do Exposure to the right?

P.S.
Yes Nikon D4 has a similar adjustment as in the 1DX AE Microadjustment


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## surapon (Sep 16, 2013)

neuroanatomist said:


> Well, what is 'underexpose'? We could also say that non-pro cameras tend to _over_expose, much in the same way that in-camera jpgs tend to be fairly saturated and contrasty, because 'most people' (whoever they are) then to prefer bright, colorful images (same reason most computer monitors are saturated and contrasty at the default calibration, and a proper color calibration with a spectrophotometer tends to make them what some would call 'dull').
> 
> Why the exposure difference? Perhaps for highlight preservation - you can lift shadows, but can't recover truly blown highlights. However, it's worth noting that on the Canon 1-series bodies you can adjust the set point of the metering with AE Microadjustment, up to a full stop darker or lighter in 1/8-stop increments (and I suspect Nikon pro bodies have a similar feature, but I don't know for sure).



+ 1 for me
Thanks you sir , Dear Teacher, Mr. Neuroanatomist , for very clear understanding for me.
Surapon


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## meli (Sep 16, 2013)

duydaniel said:


> P.S.
> Yes Nikon D4 has a similar adjustment as in the 1DX AE Microadjustment



I think every nikon from d7k on has it, separate for each mode too (spot /matrix /cw).


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## gbchriste (Sep 16, 2013)

Under (or over) exposed based on what standard reference point? The odds of any given scene in the real world having exactly the right blend of highlights, midtowns and shadows to render a prefectly exposted image with the meter needle centered are very, very low. If the scene is a little heavy on shadows, the meter behavior will tend to pull to the right. If the scene is a little heavy on highlights, the meter behavior will tend to pull to the left.

So the only way to know whether the camera - by design - is under or overexposing is to meter off a known reference.

Now as it happens, I am a devoted fan of the Lastolite EZBalance. The "normal" model is 18% gray. I shoot almost exclusively outdoor, natural light portraits with a 5D3. I have my subject hold the EZBalance right up to their face and I spot meter off of it.

And my experience has been that when I spot meter and center the needle on the very accurate 18% gray EZBalance, I do infact tend to get an image that is a little underexposed....about 1/3 stop, actually. So I now habitually kick the meter needle over to the right 1/3 step when metering off the 18% grey target.

And understanding that there is some variability in the market place for exposure/metering practices and equipment behavior, Lastolite also makes a 12% gray model. Since it is slightly darker, the meter needle behavior will be to pull to the right when compared to a reading taken off the 18% gray model under the same lighting. As it so happens, that difference is...you guessed it...about 1/3 step.

At the end of the day though, the camera doesn't underexpose or overexpose. It is up to you as the photographer to know and understand your equipment, and the theoretical and practical underpinnings of how it works and why it works that way. You ultimately are in control (unless you are shooting on full auto) and if an image is under or over exposed, it's because you under or over exposed it (equiment malfunctions not withstanding).


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## Mt Spokane Photography (Sep 16, 2013)

neuroanatomist said:


> Mt Spokane Photography said:
> 
> 
> > Many people use the AFMA feature in their Canon or the Fine tuning Feature in their Nikon bodies.
> ...


 
I'm not having a good week! I was reading the manual yesterday and read AE microadjustment as AF Microadjustment. Its something completely different, of course.

At least I read the manual, now I need to comprehend it better


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## duydaniel (Sep 16, 2013)

The point of this thread is not about how you expose your images. 
There is no standard. Some prefer darker/lighter... etc. we can talk about this for 100 years
without conclusion.

I just wanted to theorizing some reasons why manufactures adjust the cameras the way they do.
By high end cameras, I meant D4 and 1Dx.
It seems like both NiCanon slightly under exposed the image a bit when the light metering at the middle.
Maybe I am too old school but I enjoy technical stuff


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## Skulker (Sep 16, 2013)

duydaniel said:


> The point of this thread is not about how you expose your images.
> There is no standard. Some prefer darker/lighter... etc. we can talk about this for 100 years
> without conclusion.
> 
> ...



I think that the old "standard" exposure was to aim for 18% grey. That was just an arbitory choice, as I understand it. ;D

If Canon and or Nikon now think 20% grey would be better it could be for all sorts of reasons. But all sorts of possible ideas are possible, and many people will be convinced they know why. To my mind I can't think of anything more likely than preserving highlights, and I like to do that. But many people like to ETTR, so I guess they don't worry so much about their highlights.

I was advised, by a professional that I respect, to over expose bright scenes and to under expose dark ones. This was to compensate for the "standard" exposure and to make the image more life like.


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## lintoni (Sep 16, 2013)

Possibly this a hangover from the days when 'pro' cameras were more likely to be used with slide film as opposed to 'consumer' cameras that were more likely to be used with print film?


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## cliffwang (Sep 17, 2013)

neuroanatomist said:


> Well, what is 'underexpose'? We could also say that non-pro cameras tend to _over_expose, much in the same way that in-camera jpgs tend to be fairly saturated and contrasty, because 'most people' (whoever they are) then to prefer bright, colorful images (same reason most computer monitors are saturated and contrasty at the default calibration, and a proper color calibration with a spectrophotometer tends to make them what some would call 'dull').
> 
> Why the exposure difference? Perhaps for highlight preservation - you can lift shadows, but can't recover truly blown highlights. However, it's worth noting that on the Canon 1-series bodies you can adjust the set point of the metering with AE Microadjustment, up to a full stop darker or lighter in 1/8-stop increments (and I suspect Nikon pro bodies have a similar feature, but I don't know for sure).



+1. Most PS cameras are overexposed.


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## dave (Sep 17, 2013)

Well, they have got to pick a spot somewhere along the range. Like others I think that our perception of what is underxposed and overexposed (outside of extreme variation) differs depending on what you want for your shot.

I almost never shoot without exposure compensation shifted away from centre. More often this is in the + range but there are plenty of occasions where I go south (-) as well. I think in the real world it is a basically redundant question given that the ability to adjust to taste is simple to do and available to owners of all those bodies.

As long as is within a tolerance of 2/3 of a stop I don't think it really matters that much - you just adjust depending on your preference.


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## Martin (Sep 17, 2013)

Some time ago, when I switched from Nikon to Canon (D300 to 5d2) I was sure that there is a problem with my new camera (5d2) as all images were underexposed in comparison to what I was used to in Nikon in terms of exposure.
I tried to convinced myself that maybe its my mistake etc. I am and was aware of mattering and its options however the underexposed images were kind of standard with my new 5d2 and especially indoors.
I run some tests with "gray card" or any other equally lit surface (white board or wall), I've checked exposure with Nikon D300 as well as with Sekonic meter, and of course with 5d2. Checked it in different environments.
The well calibrated light meter should give an exposure with histogram with peak in the center. This is standard exposure. It does not matter if u check it on completely black surface, white or gray. The histogram should be the same. 
Test results was a little shock to me as Nikon and Sekonic gave me exactly the same exposure, and perfectly centered histogram. Canon 5d2 gave a histogram with off-centered peak (to the left), so it was underexposing obviously by (-2/3 EV or -1/2EV). The 5d2 has an exposure correction up to _+2EV so if u make standard exposure corrected with +2/3 there is not as much room for further correction (it is but not so much)
Sent it to Canon, they've checked-all in line with standards. Another shock. I've checked another 5d2 and the result was the same. Now I own a 5d3 and it is underexposing like his older brother. 

I have completely no idea why canons are metering out off the standards. A lot of users just dial +2/3 all the time. Also, have no idea why no one in canon correct this, this looks like kinda design fault, made years ago. 
What is more important, canon sensors are bad for pushing shadows as there is much banding or very poor information if any, so there shouldn't be any tendency to underexpose.


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## privatebydesign (Sep 17, 2013)

Canon cameras, and they are not alone, do not meter at 18% grey, they meter at 12% grey, that is 1/2 stop underexposed for a mid-toned subject.

Take a picture of a grey card on an auto setting and the histogram should have a spike 1/2-2/3 stop below the midpoint.

There is no 18% law, never has been. It was just a number that represented Zone V in the Zone system. Camera manufacturers use 12% as a metered norm for the simple reason that they believe that gives a more consistently "correct" exposure.

Read the small print on a Kodak grey card to see the verbose wriggling even the mighty Kodak do to try to expose an 18% grey card with a 12% meter.


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## neuroanatomist (Sep 17, 2013)

privatebydesign said:


> ...even the mighty Kodak...



Are they really still mighty?


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## privatebydesign (Sep 17, 2013)

neuroanatomist said:


> privatebydesign said:
> 
> 
> > ...even the mighty Kodak...
> ...



No, not now, but they were when they came up with so much of the stuff we take/took for granted in photography. How many companies have their own nuclear reactors in their R&D departments for instance........

How the mighty fall, imagine Apple only making cases and accessories for Samsung phones.


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## Pi (Sep 17, 2013)

privatebydesign said:


> Canon cameras, and they are not alone, do not meter at 18% grey, they meter at 12% grey, that is 1/2 stop underexposed for a mid-toned subject.



In evaluative mode, 18% or 12% means very little. In my experience, Canon's FF cameras are too protective of the highlights. Once you get used to this, it is OK.


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## Martin (Sep 17, 2013)

privatebydesign said:


> Canon cameras, and they are not alone, do not meter at 18% grey, they meter at 12% grey, that is 1/2 stop underexposed for a mid-toned subject.
> 
> Take a picture of a grey card on an auto setting and the histogram should have a spike 1/2-2/3 stop below the midpoint.
> 
> ...




Why the spike should be -1/2 or 2/3EV from center? Take professional external light meter like Sekonic, take other camera (nikon) and check where is the spike. Why do u think it is correct to have the spike more on the left side. That means underexposed image in terms of standards of course. Only Canons meter in that way.


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## alexanderferdinand (Sep 17, 2013)

An observation using the 1d4 and the 5d3 same time and light situation:
The 5d3 sets the histogram always very left. Only if contrast is high, then its in the middle.
I do not understand this strategy, because:
The 1d4's histogram is always "well centered".
PP the RAWs of the 1d always needs less shifting the EC in the converter.
So in my case: the 1d comes closer to my result ending with a print.


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## Viggo (Sep 17, 2013)

The higher end camera let's you change it if you don't like something. I have bumped my 0 EV up quite a bit, because I like my images brighter exposed.

I'm sure if I factory reset my camera I won't like it all. The beauty is that I don't have to use it like Canon might have thought I would like to use it. 

And the 1d X metering is by far the best I have used.


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## Mt Spokane Photography (Sep 17, 2013)

Skulker said:


> duydaniel said:
> 
> 
> > The point of this thread is not about how you expose your images.
> ...


 
Actually, Canon and Nikon are said to use the equivalent of a12% gray reflectance target. They use rear illuminated targets per the ANSI standard, so the 12% number is the equivalent value of a 12% gray reflectance target. As always, info from the internet may be incorrect, but this is from a person with lots of inside contacts. This equates to 1/2 stop lighter than the 18% targets, so someone using a 18% gray target to determine if their camera is exposing correctly will see a 1/2 stop difference. 

http://www.bythom.com/graycards.htm


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## privatebydesign (Sep 17, 2013)

Martin said:


> Why the spike should be -1/2 or 2/3EV from center? Take professional external light meter like Sekonic, take other camera (nikon) and check where is the spike. Why do u think it is correct to have the spike more on the left side. That means underexposed image in terms of standards of course. Only Canons meter in that way.



No Nikon also use the 12%, or very close to it, equivalent.

http://www.bythom.com/graycards.htm

Edit: I notice now Mt Spokane has already pointed some of you disbelievers to the same authoritative link. I love it when the myths and memes that people thought they understood collapse around their feet and their real knowledge gets taken to a higher level. Roll on the learning, and lest you think I think I am better than any of you, I don't, I am just at an age when I know I don't know it all, many of my presumptions are wrong, some of the people I learnt from were wrong too; but I am not so old I keep forgetting it


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## duydaniel (Sep 17, 2013)

These 12% is interesting but how does it explains 
consumer grade cameras expose differently from higher end ones?

In metering articles, the latest Nikon use 3D matrix III metering which
looks at your scene and compares it to 30,000 images database to guess the best exposures

Meanwhile all Canon beside the 1Dx use the dual 63 layer zones.
The 1Dx uses what I think is similar to Nikon that is having a lot of sensors (100,000 rgb sensors)
and run them through some algorithms to guess the exposure.

One thing disappoints me is that Nikon lets you influence the metering system using AE micro adjustment
from the D7000 when Canon only lets you do so in the 1D series


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## privatebydesign (Sep 17, 2013)

duydaniel said:


> These 12% is interesting but how does it explains
> consumer grade cameras expose differently from higher end ones?
> 
> In metering articles, the latest Nikon use 3D matrix III metering which
> ...



Even the most basic matrix metering system uses a fuzzy logic to guestimate what you are trying to shoot, it is the main reason die-hards (and slide film shooters) had such issues with matrix metering when it came out, you really don't have a clue what the camera is actually doing. The other metering modes are predictable because they don't try to work out what the scene "is" they just use illumination values, either as a center weighted average, a scene average or a spot average.

So as a specific answer to why cameras appear to meter differently, if they do, I would suggest this answer; 
People that buy lower model cameras don't necessarily know what they are doing, factory default is matrix metering (semi intelligent) and it works to get a "correct" exposure because of that intelligence. High end cameras assume a higher level of understanding and exposure knowledge and the weighting of the "intelligent" part is less as the operator is expected to have a better grasp of exposure and the amount of compensation they actually want.
Alternatively, matrix metering nails it (and it does most of the time apart from exceptional lighting situations) so is plenty good enough for everybody, but, there was such a backlash from some pros when it first came out the "intelligent" part was eased back in there cameras metering algorithms because pros are troglodytes and too slow to embrace "new" metering systems.

Maybe try exposing a Kodak card, which is known to be 18%, with a 1 series and a Rebel in matrix metering and then in evaluative metering, if my thought is correct and the fuzzy logic has a different weighting in the two cameras metering algorithm then the two matrix metered shots will be different but the two evaluative metered exposures will be the same. But that is a complete guess and I don't have Rebel. (Unless Matrix Metering is "smart" enough to know you are shooting a gray card! Which it could be, see that is the problem with Matrix Metering...........)


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## Rienzphotoz (Sep 17, 2013)

Interesting topic.


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## duydaniel (Sep 17, 2013)

Rienzphotoz said:


> Interesting topic.



This following video was comparing between cameras megapixels and stuff
BUT
it will answer the question indirectly (I hope)
between why pro camera slightly underexpose vs not so pro camera.

Look at the images!

http://youtu.be/Jg9yADZes4w


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## Sporgon (Sep 17, 2013)

It always amuses me that even with the evolved matrix metering it will still under expose a snow scene or over expose a coal hole. But I guess this is because the meter doesn't recognise the scene as white but just bright, or visa versa. 

I thought Nikon had colour sensitive exposure metering, but when I last used one it did the same thing.

Metering a scene with the light falling on it is one thing, metering to include the light source is another. My guess is that the 12% vs 18% issue is something to do with pictures often having the actual light source in them - the sky. In that situation the 'correct' exposure becomes a compromise anyway. 

The matrix metering does definitely differ between cameras; the 6D response differently to the 5Dmkii in matrix mode, but I think on a plain grey card they would be the same. I'll try it tomorrow.


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## duydaniel (Sep 17, 2013)

Sporgon said:


> The matrix metering does definitely differ between cameras; the 6D response differently to the 5Dmkii in matrix mode, but I think on a plain grey card they would be the same. I'll try it tomorrow.



I am not sure the 5D2 but 7D -> 5D3 have been using 63 dual layers zone
I believe the 5D2 used an older metering so we expect it to meter differently.


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