Exposure compensation explanation/help

[PropilotBW]

I guess I have a novice question. I have rarely used exposure compensation in my photography thus far. It's probably due to a lack of understanding. I understand the concept of E.C. tricking the camera into creating brighter or darker exposures for a specific scene.
What I don't understand is how this technique differs from just increasing or decreasing exposure in post processing? I started to believe they create the same results. If I'm wrong, please let me know so I can improve!
I have been taking portraits more frequently and I am just trying to understand the tools available to me.
Thanks!

 

[jl1975]

While you can adjust your exposure in post, getting it correct in camera is usually better. If you have a shot that is under/over exposed, you may be able to adjust it. However, if you get it correct in the first place you won't run the risk of losing details in the shadows or blowing out the highlights. Once you get too dark or too bright, you may not be able to recover those details.

 

[The_Traveler]

'Fixing' the exposure in PPing is possible but not always acceptable.
And inevitably what you are ECing for is in the shadows and try to correct that in post means increasing noise.
Example: shooting a street scene with brilliant overhead sun.
The desired correctly exposed area is the face under the brim.
Because of the general brightness the face will be well under-exposed and more noisy than optimal.
EC+ or ++ so that you lighten the shadows under the brim and give yourself the exposure and detail you need without excessive noise.

Example: note the bright overhead sun yet the faces under brims of hat are exposed enough to get decent detail.
Shot at +stop overexposure with Oly 5 and Panasonic 12-35

 

[Ysarex]

Because EC effects the camera exposure which determines what you record with the sensor. Post processing can't alter what the sensor captures -- it can only work with what you've got.

Joe

 

[DB_Cro]

I wouldn't worry about exp. comp., I never used it, I shoot full manual.

 

[JoeW]

Depending upon what you shoot, you may find very few times you need it. Or it may come essential.

For instance, if you shoot in situations with high dynamic range (some is backlit, lots of high contrast, heavy shadow), it's invaluable. If you shoot in situations where it's very easy for there to be "hot spots" or blownout parts of the photo if over-exposed, it's invaluable. If you're trying to do more than just record a setting but instead make a picture, then the ability to manipulate the light exposure will be invaluable. If you shoot at extremes (say...indoor athletics where there is poor light and fast movement), it can be useful.

And no, you can't always fix it in post. For instance, if you shoot a picture of a young child holding a puppy and you spot meter on the puppy, the "correct exposure" by the camera results in a blownout face with the child. Trying to fix that in post is impossible. Or another simpler example is this: you take a picture and look at the back of your camera to see if you "got it." If you're relying on post, what you see on your display screen will be, inevitably, an incomplete picture--you won't be able to tell if it's good enough or if you need to reshoot. Last of all, getting this element right in-camera is substantially faster than fixing it in post-production.

 

[jaomul]

EC is a great fast way of brightening or darkening a scene without having to adjust your primary settings.

In aperture priority for example you may not care what ss as long as it's fast enough to handhold but you may want a specific iso but don't want the hassle of full manual.

You take your shot but the camera meters dark or light for your taste and ec compensates quickly and easily, over riding the camera meters setting to what you want. It does this by altering the ss, if you are in speed priority it does so by altering the aperture.

Altering in pp is changing what the camera records, so there may be a little degrading of image quality, ec can allow changes of a few stops quickly and effective

 

[PropilotBW]

I wouldn't worry about exp. comp., I never used it, I shoot full manual.

I rarely use manual mode. Just trying to understand A and S priority to its fullest

 

[jaomul]

When you understand A and S mode manual will be self explanatory. Shooting manual mode is a choice, but not a cut and dry necessity. I understand manual shooting but don't use it much, but I'm just a hobbyist, however a lot of pros if you read up about them also don't shoot manual, so it's whatever suits the individual

 

[DB_Cro]

Try shooting a concert in A or S

IMHO, learning what exposure comp does will be more confusing then going over
to full manual and learning that. When you understand the exposure triangle you'll
learn to get better shots in either mode. When the need for exposure comp presents
itself, it's easier (IMO) to switch over to manual and set the exposure properly.

Do that more then a few times and you'll never end up going out of manual again.

 

[tirediron]

Depending upon what you shoot, you may find very few times you need it. Or it may come essential.

For instance, if you shoot in situations with high dynamic range (some is backlit, lots of high contrast, heavy shadow), it's invaluable. If you shoot in situations where it's very easy for there to be "hot spots" or blownout parts of the photo if over-exposed, it's invaluable. If you're trying to do more than just record a setting but instead make a picture, then the ability to manipulate the light exposure will be invaluable. If you shoot at extremes (say...indoor athletics where there is poor light and fast movement), it can be useful.

And no, you can't always fix it in post. For instance, if you shoot a picture of a young child holding a puppy and you spot meter on the puppy, the "correct exposure" by the camera results in a blownout face with the child. Trying to fix that in post is impossible. Or another simpler example is this: you take a picture and look at the back of your camera to see if you "got it." If you're relying on post, what you see on your display screen will be, inevitably, an incomplete picture--you won't be able to tell if it's good enough or if you need to reshoot. Last of all, getting this element right in-camera is substantially faster than fixing it in post-production.

This, exactly! EC is simply another tool in the box. It's not particularily useful in full manual (and depending on your brand of camera may not even do anything in manual), but it can be as Joe mentions very useful in other modes. For instance, the running shots I was doing for a local theatre production recently. The LD is using two white follow-spots and a lot of blue, red, and yellow/orange overheads. Because the main character is dressed all in white, and the background (and many of the supporting cast) are dressed in blacks/darks, and because due to the lighting I chose to shoot in shutter priority, using 1/3 - 1/2 stop of EC was necessary, or I would have hundreds of images of a blown out Tommy.

EC is nothing more than a way of telling the camera (when in auto or semi-auto modes) that you want things a little brighter or darker than it thinks they should be. That's all.

 

[tirediron]

Try shooting a concert in A or S

IMHO, learning what exposure comp does will be more confusing then going over
to full manual and learning that. When you understand the exposure triangle you'll
learn to get better shots in either mode. When the need for exposure comp presents
itself, it's easier (IMO) to switch over to manual and set the exposure properly.

Do that more then a few times and you'll never end up going out of manual again.

Really? Sorry. Not buying it. To use the example of the play once again.... Yes, I could have shot it in manual and not bothered with EC, HOWEVER... metering every single shot is not reasonable given the fast pace of the script, and the even faster changing of the stage lighting. I knew that I wanted at least 1/160 to freeze all but the fastest character movement, as well as to compensate for any camera movement when shooting at 200mm. I also knew that the lighting could change by as much as 9 stops almost instantly. Therefore, shutter priority seemed like the only sensible option, and because I needed to account for a bright, white costume, -1/3 -1/2 of EC was critical to the final exposure.

Shooting landscapes, or in the studio? Yep, 100% manual all day, every day. Going walkabout in a strange city and shooting for my own amusement? Auto every time. That way I know I'm sure to get at least an okay image; if there's time, I'll take charge and modify settings as necessary. For other things, AP or SP. Saying that one should use one exposure mode all the time is like a carpenter saying, "Always use a cross-cut saw. Don't worry about the other types. A cross-cut saw will always do the job." Yes, it will, but will it always do the best job? I would respectfully submit that it would not.

 

[astroNikon]

How does EC differ from adjusting ISO ?
From JoeW's description it's more related to manipulating the Dynamic Range capabilities.

Is it less noisy than ISO in particular situations ?
such as if at ISO 6400 and it's not quite enough, would upping EC be better than pushing ISO up ?

 

[KmH]

Not mentioned so far is that since DSLRs are mass produces consumer goods not all of a make/model meter the light such that each camera reports the exposure exactly the same.
Some cameras will under or over expose a bit, from 1/3 EV to 1 EV and we can keep EC set to compensate for that every time we release the shutter.
If it is more than 1 EV the camera should be sent in to be re-calibrated.

Note that good handheld light meters report exposure readings in 1/10 EV steps, but DSLRs report EV with less accurate 1/3 EV steps.

 

[JoeW]

When I use EC on my Nikon, it's not like resetting ISO. I end up with an exposure that my auto exposure or light meter would have told me is too dark or too light....but I intentionally wanted to do that b/c I wanted the focus on a subject's face (and don't care if the background is all black...vs. a dark background that shows detail but a face that is blown out due to over-exposure).

I used to shoot all manual. My eyes are no longer good enough for that. I have to use autofocus for a lot of shots...it's simply much more accurate than my eyesight or my judge of distance. Tirediron is spot-on regarding this issues--for a bunch of concepts (light painting or long exposures or landscapes) I'll be entirely or mostly manual. But for stuff where focus needs to be quick, it may involve distance or fast action, I find myself going aperture priority a lot of times. I'm not trying to argue against the value of shooting manual. I'm simply saying that for a lot of instances, it just isn't that workable for me. Additionally, for outdoor portraits with high dynamic range or for shooting in snow or white sand (where the reflection lies to your camera), I'm using EC probably 50% of the time at minimum.

Finally, the reason why photography can be an ART rather than just a technique or a craft is b/c there are many ways to approach creating a picture. Let's look at a hypothetical example. 3 photographers approach a landscape setting of a creek, valley, some hills and great color as the sun starts to set. One says "I'm going to set my camera on my tripod, wide-angle lens, polarizing filter to grab the clouds in the sky...long exposure so the sky gets an interesting pattern and the creek in the foreground turns in to a blur, let's go f22 on this baby....this is going to be a beautiful landscape." Second photographer says "I want to use my 200mm zoom and focus in on the woman laying down next to the creek and capture her reflection in the water...use a narrow DoF...definitely a lovely mood shot of a person playing in nature." Third photographer says "I want to capture the color in the sky, I'm going to use my EC for a faster shutter speed and play with my WB. Emphasis is on the sky with just a hint of the land. I may screw on a GND filter to help me achieve this. Shooting with my trusty 85mm lens." And they all got great photos...b/c they all looked at the setting and created a picture (of their own vision) by deciding what visual rules to apply and what camera technology to use (and what to ignore). There is no ONE RIGHT WAY. This thing we call photography becomes an art when you consciously make choices as to what artistic composition rules you follow (and which you ignore) and how you choose to use your camera. So, you should know how to use EC. And depending upon what you shoot and how you shoot, you may use it continuously. Or almost never.