Understanding Exposure - Peterson - metering

[mdsnyderjr]

I'm trying to convince myself to start shooting in manual so I'm re-reading Bryan Peterson's book Understanding Exposure. The book mentions (almost every photo) that Bryan meters off of something, usually the sky. Is he using spot metering? It seems like it wouldn't matter where you point if you are using matrix metering. With matrix metering, do I even need to "meter" off of anything or do I just pick my shutter speed and set the aperture to a correct exposure (or vice versa)?

I have a Nikon, D5100.

 

[dxqcanada2]

He is metering a specific area ... most likely with a spot meter (a centre weight meter could be used but not so accurate).

Matrix metering is the computerized version of a human spot metering multiple areas and figuring out an optimal exposure.

 

[mdsnyderjr]

So is there any point to "metering" off of something if I put my camera in matrix mode?

 

[dxqcanada2]

Not if you want to figure out the exposure for yourself.

If you want to manually (use your brain) control exposure ... then use Spot Metering, on the areas.

 

[SCraig]

Matrix metering is going to average all of the tones in its sampling area and come up with a value that matches neutral gray. If there is a lot of sky in the shot the subject will probably be underexposed. If there is a lot of shadow the subject will probably be overexposed. Using spot metering, or center weighted, shows the proper exposure FOR ITS SAMPLING AREA (which is usually very small) and ignores anything outside the sampling area. If, for example, you sample the white dress on a bride using spot metering then her face will probably be underexposed. If you sample a shadowed area with spot metering, or a dark area on an animal, the rest of the image will probably be overexposed. It is always a balancing act and you have to pick the proper area to meter from or trust your camera to meter the subject area properly.

I frequently meter on a small neutral gray card I keep in my camera bag. If I don't have it handy I've found that metering on the palm of my hand will give a very close exposure value.

 

[scorpion_tyr]

If you meter off a specific area you're either using spot metering or a handheld light meter.

 

[ph0enix]

So is there any point to "metering" off of something if I put my camera in matrix mode?

if you point the camera at the sky, you'll get a different reading than when you point it at the ground regardless of the selected metering mode.
Pick up the camera and experiment. See how moving it changes the meter readings.

 

[Crollo]

I really don't understand what you're trying to figure out here... With a scene that does not exceed the dynamic range of your medium, it doesn't matter. If your scene exceeds the dynamic range of your medium, then you figure it out. We can't decide for you what should be exposed in YOUR image. Is the terrain in your scene the dominant subject, or is the sky the dominant subject in the scene? Expose for what you want to be exposed and blow out or crush the other... Simple.

 

[dxqcanada2]

From Nikon:

[SIZE=+1]Matrix Meter is called the 3D RGB Color Matrix Meter.
[/SIZE] This meter gathers information from 1005 red, green, and blue sensors and factors in distance information provided by the lens as it evaluates proper exposure calculation. This meter instantly analyzes a scene’s overall brightness, contrast, and other lighting characteristics, comparing what is sees against an onboard database of over 30,000 images for unsurpassed exposure accuracy, even in the most challenging photographic situations. By the time the 3D Matrix meter has made its considerations of colors by hue and saturation, tonal ranges by brightest and darkest, areas of similar tonality that are connected or separated, distance to the subject, and compared that to its database generated from photographic images, it’s got a very good idea of what the exposure should be.

If you are a beginner, Matrix is where you should start. As your skills grow, and they will, you will acquire a better understand of when it might be beneficial to use other light metering options.

What is the database of over 30,000 images?
Over the years Nikon has studied the color, area of coverage, focus distance, contrast, size and shape of shadows and highlights and exposure characteristics of over 30,000 actual photographic images and incorporated this data as a reference source for the expert exposure system that is the 3D Color Matrix Meter.

 

[petto]

^^except that you know how your camera works and can make it do it what you want it to and are able understand how you got the picture you got.

Other than that it is pretty meaningless...........

 

[petto]

I disagree, using your camera in modes other than auto can teach you a lot (along with some research). You can adjust the ISO, aperture, and shutter speed and see the effects those make on the end result. Doing this in different lighting situations will give you look at how these different aspects of your camera's settings will effect the exposure of you pictures.

I am in no way saying that simply by switching the dial to "M" you will automatically know more. I am merely suggesting that in order to better understand how ones camera works you have to eventually step out of auto mode to understand the "why" behind the outcome.

 

[dxqcanada2]

I learned exposure by shooting the same subject at different settings (shutter speed/aperture) and over/under exposing based on the camera's meter reading. I noted each setting so when I got the images back I could examine what occured with each change.
Doing this on different subjects and under different lighting conditions, I was able to understand how to expose/meter.

Using manual exposure requires some understanding of how the camera's light meter works, and also being able to adjust it to expose the image as you visualized.

< not sure if I said this as I intended >

 

[impulsive1]

Understanding Exposure is practically from another era, first published in 1990. Pro cameras didn't have multi-segment metering (Matrix for Nikon, Evaluative for Canon) until 87/88, so he's likely referring to center-weighted/partial metering modes. I personally don't think much of that book.

Matrix metering is the "auto-everything" of metering modes. It sets your exposure for you. If that's what you want then use it, but I'm perplexed at why you'd be reading a book like Understand Exposure. Spot metering is the mode for people who want total control over exposure. However, the problem with controlling exposure is that you have to actually do it...you have to be able to set the desired exposure if you want your images to come out right. If you read the book you should get some idea of how to do this.

Just a note...there's no benefit to shooting in manual. Manual is good for times when the meter doesn't work, as with astrophotography, long exposure photography, and certain types of flash photography. But with modern auto mode functionality, if the meter works then manual mode is the wrong mode. You'll get more from an auto mode. Also, the shooting mode has nothing to with setting exposure or anything to do with the metering mode. All techniques used to determine correct exposure are equally valid in Program mode as they are in manual mode. It truly means nothing to be shooting in manual mode.

So, you're saying that while shooting a basketball game in a gym with less than desirable light, I would be better off in auto mode? Mind you I need to freeze action.

 

[minooo]

MATRIX has evolved very much. I believe soon it will be able to recognize faces and expose after them. I see that matrix mode guesses many conditions that in the past where wrong, like a small black subject on a bright background, or a white bride dress, etc. These were impossible images in auto, now it works almost every time. if the minilabs would use the same principle...

 

[minooo]

Those shots were never impossible. You simply had to do what you would do in manual mode...compensate your exposure.

I am talking about the camera on its own metering. The new cameras, since D90, I noticed that just do the job out of the box, no compensation.

As about face detection, I am not talking about live view, but viewfinder metering and exposure. Maybe you are right, I just detailed for better understanding.