tcanzano Loc: Bristol, NH

I am having a little bit of a hard time grasping Exposure Compensation. I understand that you are either adding or subtract from your exposure. So if you are doing a snow scene it seems you would subtract because the snow reflection is throwing off your metering. Do you adjust after you have your setting or before? What are other examples you would use a - or +? On a very cloudy day when you take a shot and it comes too dark, I would imagine you add?

CHG_CANON Loc: the Windy City

Actually, you'll typically 'add' EC for snow situations. The camera meter will tend to make things 'gray'. So, you want to tell the camera to make the white 'white' via adding exposure rather than darkening.

The best way to discuss these types of issues is using actual examples from your camera. That is, attach JPEG files un-edited and directly from your camera, being sure to store the actual file. This allows the community to access the image, to see both the pixel-level details and the EXIF data that contains the camera and lens settings. From these exact details, we have a common basis of a detailed discussion and can then provide actionable and relevant changes you can make to your camera.

Longshadow Loc: Audubon, PA, United States

Welcome to the forum.

You have the basic concept.
For me it would depend on how the meter sees the scene and the result I get.
If the result is too bright, I would expose less (-)
If too dark, I would expose more (+).

tcanzano Loc: Bristol, NH

Thank you both for a quick reply.

tcthome Loc: NJ

What CHG CANON says is correct. The cameras meter always tries for 18% gray which considered neutral. The camera meter on 0 would tend to make the snow look a little on the grey side. Exposing to the right, ETTR, would help with this. Same for a black cat, = under exposing for a black cat should help.

DirtFarmer Loc: Escaped from the NYC area, back to MA

One of the best things about digital photography is that you can try again right away if you don’t like what you see on your monitor. That enables you to make corrections in real time and get a feeling for how to deal with it.

Digital photos are basically free. Experiment.

Longshadow Loc: Audubon, PA, United States

R.G. Loc: Scotland

Your mistake shows the counter-intuitive nature of EC. The usual purpose of using EC is to compensate for when your camera's meter is going to give you a wrong exposure. To understand that you need to understand how your camera's metering can be caught out.

If a scene is predominantly bright (e.g. snow in daylight) you may think the last thing you need to do is tell the camera to increase the exposure. However, in those circumstances your camera will meter for the preponderance of brightness and it will deliberately keep the exposure low. A typical value of EC for snow in bright daylight is +1 or more.

If a scene is predominantly dark but has bright highlights (small bright areas) that you don't want blown, you need to use negative values of EC to save the highlights. Intuitively you would want to increase the exposure for a scene that's predominantly dark, but that would result in the highlights being blown.

Most things can be corrected in post processing, but when highlights are lost through being blown, they're gone for good and you can't recover them in PP. Underexposing may not be ideal (because of the increase in noise when you brighten in PP), but nothing is lost, and noise is treatable (up to a point) in PP. How much negative EC to use is something you need to learn because it depends on your camera and also on how extreme the lighting is in the scene. If movement* isn't a problem, exposure bracketing is a good solution, but it needs computer software to do the merging of the bracketed shots.

(*Even with movement in the scene, anti ghosting can be used in the merging process. Large movements are usually OK but the software may not pick up on small movements - which can add softness to the final image).

MikeMck Loc: Southern Maryland on the Bay

I spent several summers in the 50's going to the Groton School Camp on Newfound Lake at Mayhews Island. Love Bristol.

PHRubin Loc: Nashville TN USA

1st - WELCOME TO UHH!

The meter in a camera expects scenes to be average in brightness as 18% grey. But a snow (or beach) scene is actually much brighter than average, so you have to tell the camera to make it brighter, or ADD using EC.

wdross Loc: Castle Rock, Colorado

What kind of camera? If it is a DSLR, because there is a mirror, it may not show the snow the way you want it to appear. If you are shooting mirrorless, it should be showing the scene as it would appear taking the shot.

Assuming DSLR, all meters try to determine a scene as 18% gray. That means the meter will make that white snow scene "gray" exposure wise. To get the "gray" snow scene back to white snow will require adding exposure to the metered exposure to "overexpose" your snow back to white from gray. It should require about a 1.5 to 2 stop increase of exposure.

The best demonstration of what your meter is doing is to take white, gray, and black construction paper (or other suitable items) and meter off them. While shooting in the exact same lighting, fill the viewfinder frame with each one of the papers and meter off the papers. Each image will be gray. If you take note of the exposure differences, it will give you an idea of the corrections needed by your camera to make the "gray" white back to white again and the "gray" black back to black again.

amfoto1 Loc: San Jose, Calif. USA

No...

When you're shooting an unusually bright snow scene, that will cause the camera to want to under-expose in any of the auto exposure modes... so you need to override it and dial in some plus E.C.

If, on the other hand, you are shooting a black bear in a coal mine the camera will want to over-expose, so you need to dial in some minus E.C.

How much E.C. is needed depends upon the scene... if it's only partially snow covered and a mix of tonalities it would require less than a heavily snow covered scene that has very little other than bright white.

The meter's angle of view setting makes a difference, too. For example if you're using spot metering it will only be measuring a very narrow portion of the scene and you need to make any adjustments based upon that particular area within the scene. Partial metering is a larger area, but still restricted to only part of the scene. Center-weighted is sort of an "old school" metering pattern... where the entire scene is measured, but some extra emphasis is put on the central area (the size and shape of that central area varies depending upon manufacturer and camera model... it also changes to some extent depending upon lens focal length... you might find more info in the user manual or at the manufacturer's website). A more "modern" variant is called "matrix" or "evaluative" metering.... This also measures the entire scene, but it tends to put more emphasis on the area right around active AF points. This works better when subjects aren't always being centered.

In general, the narrower the area being metered, the more careful attention to E.C. will be needed. Wide scenes often have a mix of tonalities that average out, while spot metering often is only measuring a single tonality.

It's hard to teach people how to use E.C., other than the generalities. Best thing to do is learn to "see" the scene's tonal ranges (try to think in black, white and gray rather than colors), look for things that aren't "average", take a shot with settings you think will work and then check the histogram, reshoot as needed. Also watch what you tend to do in post-processing. If you find you're having to increase exposure in many or most of your images, you are tending to under-expose and might adjust accordingly. On the other hand, if you are seeing your highlights blown out in many or most of your shots, it may be that you tend to over-expose and need to dial things back a bit.

Keep in mind that the camera doesn't know what it's pointed at. Camera metering systems are designed to assume everything is "average gray" and make auto exposure settings based on that assumption. If you think about it, that's all the meter can do. It can't distinguish white from black from gray or green or red or yellow. As a result, when things aren't "average", the exposure will be off. And that's why E.C. is provided, so the user who can take those things into consideration can override what the camera and it's metering system want to do.

Purely manual exposure (even no Auto ISO) is another matter. Here you do a manual form of E.C. yourself, by varying your settings from any meter recommendations.

Yes, mirrorless cameras with an electronic viewfinder can give a pretty good exposure preview. The image displayed in the viewfinder may not be totally accurate, but reasonably reliable. Many DSLRs and mirrorless without a viewfinder can display some sort of exposure preview on the camera's rear LCD. Take that with a grain of salt, though, because it's heavily influenced by ambient light conditions and those screens aren't particularly well calibrated. With both the EVF and rear screen Live View, the histogram is a more reliable source of info about exposure. Learn to read and use those.

gvarner Loc: Central Oregon Coast

Go to YouTube and do a search on "exposure compensation". You will ne able to see the "why" of doing it. A light meter wants to record everything as 18% neutral gray. If you have white snow, it will try to make it darker to be closer to gray. Thus you open up the aperture to fool the meter and render white snow to look white. Same goes for a black dog. The meter wants a gray dog so you close the aperture to make the dog look darker.

Earnest Botello Loc: Hockley, Texas

Welcome to the Hog, enjoy.

josquin1 Loc: Massachusetts

A book that is always good to read is Ansel Adam's The Negative. In it he explains his zone system in which he explains the need to increase exposure for snow if you want it white and not gray.