An experiment with Exposure Compensation...

I wanted to learn more about the function and/or ability to choose Exposure Compensation with my Nikon D3500, so I took this photo just now, after I got home from work, of the full bloom rosebush flower in the backyard.  I knew (from previous photos) not to go full wide open, f/1.8 and things like that....  I backed off a hair to f/2.5 and held extremely still at 1/60 shutter and prayed the wind wouldn't blow.  I pressed the button for exposure compensation and backed it down a bit too (can't remember how much), just to see if it would darken the photo a little more.

What do you think? When is it best to opt for Exposure Compensation vs just letting the camera do whatever it chooses and adjusting it in Photoshop or Lightroom? How often do photographers use the Exposure Compensation function? Educate me, please...

The camera's light meter tries to make everything 18% gray. I use exposure compensation when there is either a lot of black or a lot of white in the setting. The camera will want to make the blacks gray and the whites grayish. This explains why lots of inexperienced photographers take pictures of gray snowscapes.

In this particular image, I wouldn't be thinking exposure compensation unless I was looking for a particular artistic effect. Although I do wonder about your Nikon's exposure choice. The tops of the upper petals are almost at the point where they would be blown out at f/1.8. If I were taking this shot, I would have upped the ISO so I could use a smaller aperture that would get all the petals in focus.

Exposure compensation is used to control your exposure when you're shooting in automatic mode.
I typicaly shoot in manual mode with auto-iso, so the camera will try to make every scene 18% gray unless I dial in some compensation. If I'm shooting a white bird on a bright sunny day, the camera will overexpose the white unless I dial exposure way down. Do't want to blowout the highlights.

The first thing to grasp is that the camera only has 3 properties to control the photographic exposure* - Aperture, Shutter speed and ISO.

That's it, nothing else.

So when you are shooting in either full automatic mode or a semi-automatic model (like aperture priority or shutter priority), the camera is controlling one or more of those values all the way up to controlling them all (full auto). As noted by the others above ,the meter inside the camera aims to get everything to a set grey value** of exposure.

However in many light conditions the camera meter is not perfect and it can be tricked. A common example is taking a photo of a snowy landscape. If you let the camera do the exposure itself it will generally render the scene very grey, not white. It basically ends up underexposing the photo because there's all that bright white snow everywhere that its trying to get to grey with.
Another common one is bright sunshine where you might notice the highlights of a scene getting clipped (overexposed) as whilst they are part of the scene, they are far brighter than the general elements in the scene.


Exposure compensation is your means to tell the camera to either over or under expose from its meter reading using the setting(s) that it has control over. To tell it to overexpose a little when shooting in snow or to underexpose in bright conditions.
In your flower above you've got some highlights on the upper portions of the flower which are indeed quite a lot brighter than some of the lower and middle points of the flower. Therefore using a little underexposure has likely helped darken those highlights and stop them blowing out.

In editing you do have some exposure controls, however the limit with them is that they have to work with whatever data your camera captured at the time of taking the shot; they can't "add" data if none was recorded (full under/over exposure). Now the limits for this have increased over the years as digital technology has advanced, indeed the ISO invariant sensors on the market have really opened up those limits into the extremes. Things that 10 years ago which were impossible. So in some sense you've got a lot more freedom today to "make an exposure mistake" and still have data to work with in editing. However its still good practice to "get it right in camera" as that gives you the best data (exposure) to work with. It also is morally boosting when you're glancing at the back of the camera and helps cut down on editing work.

*strictly speaking its 2, but 3 is generally easier to wrap your head around in a practical sense of how you interact and work with the camera.

** 18% grey is often quoted, though I'm led to believe that this is not an industry standard with digital cameras and that it can vary. However for the vast majority of people the actual value doesn't matter, only that its the same value with the same camera each time.

ButchA61 wrote in post #19288706
When is it best to opt for Exposure Compensation vs just letting the camera do whatever it chooses . . . ?

Even EC = 0 is a choice.

What the camera chooses will depend on what shooting mode you're in (Av, e.g.), what other settings you select, and the light in the scene. Only you can adjust for troublesome scenes where some parts of the scene are much lighter than others. My camera is less sophisticated than those of most here, but it has a feature other than EC that helps. Pushing one button makes available three choices for metering: evaluative, center-weighted average, and spot. This feature is worth experimenting with by taking a lot of shots with the three choices and seeing what you get. Use spot metering when you want the camera's light sensitivity to be led by the brightness of light in the small part of the scene that you're aiming at.

Checking the histogram before shooting will tell you whether your settings for exposure are about right. I'm still trying to make it a habit.

So if you have to shoot in the middle of the day, say a sporting event that you don't have control of the time, does it help to move the EC to the left (negative) a bit? I see some of the highlights getting clipped, like a blond haired athlete for example.

You can't fix bad exposure in the post. It will looks like bad exposure fixed in the post.

On your example bright object is in the middle. Surrounded by less brighter area.

If you have exposure metering mode at default, it measures entire frame. And it might make you main object darker, because in this mode it wants to have average across the frame exposure. To correct it you could use exposure compensation. To bring brightness of your main object as you like.

Or, since the object is right in the middle you could switch metering mode to the center, where object is. It will also give correct, but auto exposure.

Or you could switch to manual mode, select shutter speed to be non wind dependent, aperture to have DOF as you like and ISO to support both with correct exposure of your main object.

From all three I prefer exposure compensation and across the frame metering. With mirrorless, live view it is quick dial and visible in real time. With OVF I take test shot to see how much I have to correct.

duckster wrote in post #19290925
So if you have to shoot in the middle of the day, say a sporting event that you don't have control of the time, does it help to move the EC to the left (negative) a bit?

Yes, it helps. This image, reduced in size from one I posted recently, shows what happens when you pay too little attention to bright spots in the scene. A woodsy urban park for small children, late September. It was late afternoon, not midday, but the sun was strong and, being filtered through trees, it picked out a few places in the mulch, making them very conspicuous and not fixable. The settings not shown above the photo were Tv mode, auto ISO, EC = 0. I should have dropped EC to –1/3 or –2/3.

duckster wrote in post #19290925
So if you have to shoot in the middle of the day, say a sporting event that you don't have control of the time, does it help to move the EC to the left (negative) a bit? I see some of the highlights getting clipped, like a blond haired athlete for example.

As others noted, this is indeed correct. Sometimes you might even be a full stop under-exposed on the exposure compensation to counter a bright day. Another aspect which helps is to check the histogram (either live if your camera has it or in a shot after its taken). Histograms are simple to read and invaluable on the camera and its good to use them for photo review

The left side of the histogram is under exposure (full black, no data); the right side is full over exposure (full white, no data). In an ideal world the greatest amount of the bars want to be as far over on the right side without actually touching the full right side itself. Giving you the most light data with no over exposure. Of course this is only an idealistic exposure theory and you have to balance it against other things, for example in a sport it might be having enough shutter speed to freeze the motion etc... Newer sensors have also started to make this theory a little less critical as data recovery from dark regions is no where near as noise generating as it was in the earlier days of digital photography. Again its good practice to "get it right in camera" as much as you can.

Another aspect is that when you review a shot with a histogram view enabled the areas overexposed will blink on and off. This means it not only tells you that you've got areas overexposed, but roughly shows you where. Sometimes a grey sky might well overexpose and that's fine. It's a low detail area and a little overexposure there is acceptable if the rest of the shot looks good.

kf095 wrote in post #19290937
You can't fix bad exposure in the post. It will looks like bad exposure fixed in the post.

This is true only if you have clipped highlights and thus don't have any digital data to work with, or if the shadows are so black and the camera introduced bad electronic noise in the dark areas. However if a camera has great DR and your entire scene, underexposed or not, fits within that range, you can recover any parts of it, selectively or entirely with good tools, to the point it didn't matter if you got the exposure correct or not.

There is a point where the analog ISO gain and the digital ISO gain are pretty darn close to each other, if shot in camera with analog gain vs post processing with digital gain.

OhLook wrote in post #19290982
Yes, it helps. This image, reduced in size from one I posted recently, shows what happens when you pay too little attention to bright spots in the scene. A woodsy urban park for small children, late September. It was late afternoon, not midday, but the sun was strong and, being filtered through trees, it picked out a few places in the mulch, making them very conspicuous and not fixable. The settings not shown above the photo were Tv mode, auto ISO, EC = 0. I should have dropped EC to –1/3 or –2/3.

Hosted photo: posted by OhLook in
./showthread.php?p=192​90982&i=i173843875
forum: Critique Corner

That is a tough one for sure, I have hit similar situations often. Many times after I already took the shot and left, then later realized I probably should have double-checked while on scene. This is why weddings can be very frustrating for me. I don't typically drag strobes around with the couple and an onboard flash doesn't help much either when doing outside shots.

Bald gentlemen and flowers/dresses always cause me grief. I was careful on this shot, I shot probably about 1 stop under with EC and then brought things back up as needed in post.

TeamSpeed wrote in post #19291243
That is a tough one for sure, I have hit similar situations often.

Camera sensors just don't have enough dynamic range! I don't recall that those patches on the ground at the park were so glaring. Maybe they were and I missed it because the general area, with trees around, was well shaded and gave an impression of dimness.

Bald gentlemen and [white?] flowers/dresses always cause me grief. I was careful on this shot, I shot probably about 1 stop under with EC and then brought things back up as needed in post.

This shows the true conditions we were working in, brutal midday sun and the ceremony location having people facing the sun. Worst two conditions to deal with... This is why I wish people would plan the wedding with the photographer as well as the wedding planner, so they could point out things like this well in advance. In any case, I use auto ISO but swing the EC as needed depending on where I was shooting.

Even with whatever EC you applied, both shots look overexposed to me, esp. the second. ISO 500 and 200, it says. ISO 80 would have been plenty.

OhLook wrote in post #19291277
Camera sensors just don't have enough dynamic range! I don't recall that those patches on the ground at the park were so glaring. Maybe they were and I missed it because the general area, with trees around, was well shaded and gave an impression of dimness.
Even with whatever EC you applied, both shots look overexposed to me, esp. the second. ISO 500 and 200, it says. ISO 80 would have been plenty.

The second is for sure and was more of a reference shot. When I process images, I know what the family is going to use the files for and in this situation, they were printing locally at a pharmacy.

When this is the situation, I process the images to be a bit brighter than normal because the prints always come out darker than what all of us see on our various monitors, whether calibrated or not.

That being said, the POTN histogram seems about what I wanted the file to be.