Exposure Compensation v. Spot Metering

[Picsel]

I am relatively new to photography. I will be traveling soon with a Nikon D5300, and plan to photograph sunsets with the sun setting into the ocean horizon. I will be using aperture mode and manual mode, and possibly shutter priority mode. I have been learning, but cannot quite get my arms around the concept of exposure compensation v. spot metering. I will shoot in RAW, but my editing skills are extremely basic. So, my questions are . . .

Are these two techniques accomplishing the same thing? Is there a time to use one over the other? As a newbie, which one would you recommend I use when shooting sunsets? Any advice on how to use them? For example, do you have recommended exposure compensation number? Are there any modes that do not allow spot metering or exposure compensation?

Thanks in advanced for your advice. I really appreciate it.

[Manfred M]

Welcome to CiC. Would you mind clicking the My Profile button on the top of this page and at least giving us your first name and where you are from. We are a fairly informal group here at CiC and go on a first name basis.

I'm going to move your posting to the General Photography Discussion forum, as you are going to receive more answers if it is located in that forum.

Rather than worry about exposure compensation and spot metering, I would suggest that you learn how to use your camera's histogram, as this is the most important tool you will have for this (and any) kind of photography. You will want to get as wide as possible of an exposure without clipping either the blacks or the highlights. In sunset shots, if you are shooting directly at the sun, there is no doubt that you will likely blow out the highlights, so getting enough data for the rest of the scene is critical for a good shot.

Back to your question, you have to understand how your camera's exposure meter works. It is a reflective meter, which means it gets the readings of the light reflected off your subject. Camera manufacturers have set their meters so they work well for an average scene. If you are shooting this hypothetical scene, in black and while and averaged out all the tones, the image would be a neutral gray (about 18% gray). If you want to test this, take a picture of a black surface, a gray surface and a white surface. Your camera (if you are not shooting in manual exposure mode) would give you identical results.

What exposure compensation does is lets you override what your camera, through the metering is trying to do. It will take a night scene and make it too light, so by using exposure compensation, you can tell your camera to give you a darker exposure. If you were shooting a snowy scene, your camera would make it too dark, and again you can override what your camera is trying to do by using exposure compensation. The way you determine how much compensation you need is by looking at your histogram and adjusting it so your camera captures a good distribution of light that you can then use to create the image you want in post processing. If the exposure is to dark, use + compensation and - when it is too light. There is no rule of thumb on estimating how much compensation to dial in. Experience and your histogram are your best guides.

Spot metering is still reflected light metering, but instead of getting a light reading of the entire scene, it will base the exposure on the reading of a small area in the centre of the image. It will still base that exposure on giving you a neutral gray. You will still need to read your histogram to ensure that the exposure is correct for the scene.

One mistake a lot of people make is to try to judge their exposure based on what the screen on the back of the camera shows. This is quite unreliable as the ambient light conditions will heavily influence how the shot appears and the exposures tend to be off.

The only modes where exposure compensation is not required is when you shoot in manual exposure mode. Here you get to do everything yourself. I believe Nikon ignores any exposure compensation settings when shooting in manual, but cannot be 100% sure. Test this yourself or check your manual.

[Mike Buckley]

To add to Manfred's helpful information...

Is there a time to use one over the other?

It's important to keep in mind that you can use any metering mode with or without exposure compensation to achieve the same exposure. So, the metering mode combined or not with exposure compensation that you use especially in your initial foray into photography is the metering mode that you are most comfortable with. You'll be most comfortable with the mode that most consistently delivers the results you want to achieve.

As an example, some people usually use spot metering and I never use it. That's because I'm not good at it; I'm very bad at determining which luminosity is the ideal luminosity to meter.

So, find a metering mode that works for you at least in the initial stage of your learning curve. Probably fine tune it using exposure compensation. And as Manfred explained, always check your histogram and adjust your exposure if needed using whatever method of making the change works easiest for you. For me, it would be using the exposure compensation. Perhaps so or perhaps not for you.

[DanK]

Manfred nailed it, but I'm going to suggest a rearrangement of the key points that might help simplify things.

1. The first fork in the road is this: do you use the meter's information to set the exposure? In manual mode, you set it. In all other modes, the camera does it.

2. Regardless of #1, you have to decide what parts of the image the camera will use for metering, and how much weight it gives to each part. I don't think I have ever taken a shot with a Nikon, but I think your camera has three options: matrix metering, which uses the entire frame but uses a proprietary algorithm to estimate exposure; center-weighted, which uses the whole frame but gives more weight to the center area; and spot metering, which uses only a small area and ignores all the rest.

3. If you let the camera choose the exposure--if you are in any mode other than manual--you can tell the computer to increase or decrease exposure relative to its guess. That is what exposure compensation does. This is true regardless of your choice in #2, but your choice in #2 may determine how much compensation you need. The numbers are stops, so +1 exposure compensation would have the same effect as opening the shutter twice as long or opening the aperture one stop, e.g., from f/8 to f/5.6.

4. The last issue is: if you are going to use exposure compensation, how do you know how much to use? As Manfred says, the answer for any given image will appear in your histogram. If it hits the top edge, darken the exposure until you get a histogram that doesn't. And increase exposure if you run off the bottom end. There are some rules of thumb--snowy scenes typically require +1 or +2--but at this stage, your best bet is not to look for rules of thumb but rather to use the histogram.

[pnodrog]

Warning: Nikon and Canon apply exposure compensation differently and it is most apparent in manual mode. I understand Canon ignores exposure compensation in manual mode. Nikon's "philosophy" is to apply the exposure compensation prior to displaying it on the exposure bar indicator so in manual you are adjusting to an offset meter display.

To check - in manual mode with no compensation (and a static subject under steady light) set the exposure to the center of the bar using aperture or speed (Make sure auto ISO is off). Now dial in a negative 2 stops exposure compensation. When you look back in the view finder you will see it is indicating that the exposure is now two stops over. So Nikon does apply the compensation in manual mode.

[george013]

Warning: Nikon and Canon apply exposure compensation differently and it is most apparent in manual mode. I understand Canon ignores exposure compensation in manual mode. Nikon's "philosophy" is to apply the exposure compensation prior to displaying it on the exposure bar indicator so in manual you are adjusting to an offset meter display.

To check - in manual mode with no compensation (and a static subject under steady light) set the exposure to the center of the bar using aperture or speed (Make sure auto ISO is off). Now dial in a negative 2 stops exposure compensation. When you look back in the view finder you will see it is indicating that the exposure is now two stops over. So Nikon does apply the compensation in manual mode.

Nikon changes the offset, the 0-point, of the exposure bar indicator. It doesn't change the settings. So showng a difference of 2 stops, the setting will stay the same.

In matrix metering Nikon will analyse the scene. In average that can work, but not always. I read once but didn't try it jet, when you take an exposure of the sea with the horizon in the middle, this exposure will change when you turn the camera 180 degrees. Nikon gives more value to the foreground, the bottom off the image.

As said before, the histogram and the screen with the blinking fields showing clipping are the tools to work with. The first one shows you if there's clipping, the second one where the clipping is. The histogram also shows if there'is room to change exposure.

When shooting in manual I always set exposure value compensation to 0. To get a consistent exposure bar indicator.
George

[dem]

Exposure Compensation and Spot metering are not mutually exclusive - you can use them at the same time. For example, if you spot meter off a black object the camera will adjust the exposure to make it look mid grey. But if you dial -2EV, then this object will be black in the photo. Same with a white object. The spot metering will make it look grey, but with +2EV you can make it white again. In fact some cameras have 3 spot metering: for black, for grey and for white. If yours does not, you can replicate this function by using Exposure Compensation as above.

Exposure Compensation behaves differently on different cameras only in Manual Mode when Auto ISO is on. It either adjusts Auto ISO or has no effect on exposure.

I rarely use spot metering, but let the matrix metering decide on the exposure, then check the histogram and then adjust EV if required. Or go all manual if there is time to adjust shutter speed, aperture and ISO to suit the scene.

[RobFellows]

Hi, the comments so far are plenty detailed enough so I won't go there and repeat like a parrot.

If you want to get nice sunset pictures with your D5300 you can turn on the bracket function. Set the value to either 2 stops or 3 stops, leave it in matrix metering and let the camera work it out. If none of the single shots contains enough data (blown highlights or black shadows) then you can always merge them in Lightroom or similar.
Just remember it is better to pull down highlights than to increase the shadows if you want to avoid noisy images.

Spot metering is great if you want to get creative with silhouettes or photograph things like a bird in flight, not really great for sunsets unless you really know what your doing (I don't).

[loosecanon]

Remember for important photographs you can set the camera to bracket the exposure - 2 stops is often about right, and of course with high contrast subjects like sunsets you can always combine exposures - either as a HDR process or more simply as layers. So long as you have your raw files you can do the editing anytime in the future - just make sure you come home with images you can work on.
I keep one of my custom settings (Canon camera) set to -1/3 exposure compensation, bracket 2 stops, Aperture priority. A feature of Canons is that if not on single shot, when set to bracket exposures, pressing the shutter fires three shots and then stops.

[pnodrog]

Exposure Compensation behaves differently on different cameras only in Manual Mode when Auto ISO is on. It either adjusts Auto ISO or has no effect on exposure.

Are you absolutely sure? There are a number of threads on other sites where Canon owners are lamenting the fact that exposure compensation is not available in manual mode regardless of whether Auto ISO is on or off.

In manual mode Nikon does offset the metering bar by the exposure compensation and if Auto ISO is on this compensation is applied. Effectively giving a totally new auto-exposure mode. I have never tried it but there are several articles discussing the advantages of using this exposure method as the photographer has absolute control over shutter speed, aperture and exposure compensation but still has the exposure automatically adjusted by the changes to ISO.

[DanK]

Are you absolutely sure? There are a number of threads on other sites where Canon owners are lamenting the fact that exposure compensation is not available in manual mode regardless of whether Auto ISO is on or off.

I believe that is correct. I only rarely use Auto ISO, so I just checked with my 5DIII. The manual states that EC is available in P, Tv, and Av modes. There appears to be no way to turn it on in manual mode. In Tv and Av, it is controlled by the back wheel, but in M, the back wheel controls aperture. If you turn on AEB with auto ISO in manual mode, the camera brackets with shutter speed, not ISO.

I would prefer to have a way to bracket or compensate with ISO. One context in which I have found auto ISO useful is in shooting no-flash events. If the lighting is low, it is particularly important to ETTR, because the degradation from underexposing is much worse at high ISOs. If you notice from the histogram that a shot could use more exposure, you would have to take it out of auto ISO, reshoot, and put it back into auto ISO, and that takes too long for some events.

[pnodrog]

I believe that is correct. I only rarely use Auto ISO, so I just checked with my 5DIII. The manual states that EC is available in P, Tv, and Av modes. There appears to be no way to turn it on in manual mode. In Tv and Av, it is controlled by the back wheel, but in M, the back wheel controls aperture. If you turn on AEB with auto ISO in manual mode, the camera brackets with shutter speed, not ISO.

I would prefer to have a way to bracket or compensate with ISO. One context in which I have found auto ISO useful is in shooting no-flash events. If the lighting is low, it is particularly important to ETTR, because the degradation from underexposing is much worse at high ISOs. If you notice from the histogram that a shot could use more exposure, you would have to take it out of auto ISO, reshoot, and put it back into auto ISO, and that takes too long for some events.

Thanks Dan. I do not have a Canon but your explanation confirms my understanding that EC is ignored when it is in manual mode.

[Mike Buckley]

To make things a bit more complex, consider that older Nikon cameras (such as mine) add an external flash's exposure compensation to the camera's exposure compensation. At least some of the high-end cameras, with some of the newer Nikon cameras, the flash's exposure compensation overrides the camera's exposure compensation rather than adds to it. I have heard that in all Canon camera systems the flash's exposure compensation overrides.

[pnodrog]

To make things a bit more complex, consider that older Nikon cameras (such as mine) add an external flash's exposure compensation to the camera's exposure compensation. At least some of the high-end cameras, with some of the newer Nikon cameras, the flash's exposure compensation overrides the camera's exposure compensation rather than adds to it. I have heard that in all Canon camera systems the flash's exposure compensation overrides.

I rely on this behavior when I am taking interior shots in rooms with windows to views. I have the the camera's EC set to between -2 and -3 depending on how bright it is outside and the flash set to +3 or +4 and bounced off a ceiling. (The metering is taken from interiors ambient lighting) I know there are more accurate ways to determine the exposure (spot metering etc) but I am usually in a hurry and my method gets the exposure close enough that it is easily tweaked in PP.

[William W]

Are you absolutely sure? There are a number of threads on other sites where Canon owners are lamenting the fact that exposure compensation is not available in manual mode regardless of whether Auto ISO is on or off.

Around November 2013, Canon announced that the EOS-1D X was to be the first Canon DSLR to get exposure compensation in Manual mode with ISO Auto. Just after that date CPN and Chuck Westfall (independently) announced that other Firmware Updates would follow for some other EOS cameras, I don't have at hand the (very short) list of those Cameras.

WW

[William W]

I am relatively new to photography. I will be traveling soon with a Nikon D5300, and plan to photograph sunsets with the sun setting into the ocean horizon. . . .

As a newbie, which one [Exposure Compensation - or - Spot Metering] would you recommend I use when shooting sunsets?

Neither. Use MATRIX metering and BRACKET 6 exposures: -4; -3; -2; -1; 0; +1

If you review your work arduously you should learn more and anyway you'll have a range of image files to learn more about Post Production.

*

Thanks in advanced for your advice.

Not a good idea. It would be more beneficial to you to engage in the discussion.

WW

[Polar01]

William for your info the D5300 will only do 3 shot bracket, so Picsel would not be able to shot a 6 shot bracket.

Cheers: Allan

[William W]

Around November 2013, Canon announced that the EOS-1D X was to be the first Canon DSLR to get exposure compensation in Manual mode with ISO Auto. Just after that date CPN and Chuck Westfall (independently) announced that other Firmware Updates would follow for some other EOS cameras, I don't have at hand the (very short) list of those Cameras.
WW

FYI - My file copy, edited now for brevity, my bold now for emphasis:

[BEGIN FILE]
"October 22, 2013:
“Canon Firmware Upgrades for the EOS-1D X and EOS-1D C Digital SLR Cameras Deliver Improved Creative Control and Convenience . . .

“Firmware Version 2 for the EOS-1D X is Based on Extensive User Input and Provides More Efficient Autofocus Performance in Low Light, Custom Controls, and Improved User-Programmed Functionality. . .

Improved Operability for the EOS-1D X
Developed as the ultimate Canon EOS camera, the EOS-1D X Digital SLR is designed with foresight that enables its performance to be periodically improved with new firmware upgrades, helping to ensure maximum long-term value for owners and users of the camera. These improvements are engineered to support and advance the evolving creative needs and business imperatives of professional photographers and committed high-end amateurs. The features provided by firmware version 2 are designed for more efficient automation that takes the task of changing settings away from the “heat of the moment” and enables photographers to concentrate on creativity and obtaining valuable shots. Firmware version 2 upgrades and operability additions include a total of 10 features that are now new or improved:
AF Performance with Moving Subjects –[edit]
Enhanced AI Servo AF Performance in Low Light Conditions – [edit]
Improved Acceleration/Deceleration Tracking Parameters – [edit]
Selection of Initial AF Point While Shooting in 61-Point Auto Selection AF – [edit]
AF Point Switching According to Camera Orientation – [edit]
Expanded Minimum Shutter Speed in Auto ISO – [edit]
Exposure Compensation in Auto ISO with Manual Mode Set – This new function enables photographers to manually set a desired shutter speed and aperture, use Auto ISO to control the exposure, and use Exposure Compensation to adjust the exposure for challenging lighting conditions (e.g., a very dark or very bright background). This new function can be activated through the Quick Control Dial or by using the Main Dial while pressing the SET button.
Toggling Between Alternate Camera Settings – [edit]
Same Exposure for New Aperture in Manual Mode – [edit]
Display Protected Images Only – [edit]
. . .
New Firmware Release Schedules and Installation Procedures
Firmware version 2 for the EOS-1D X Digital SLR camera is scheduled to be posted on the Canon U.S.A. website in January 2014. Users will be able to download and install the new firmware on their own, or have it installed by an authorized Canon Factory Service Center. . . ."
[END FILE]

REF: CPN – WMW Filed

[William W]

William for your info the D5300 will only do 3 shot bracket, so Picsel would not be able to shot a 6 shot bracket.

Cheers: Allan

Yes the D5300 can only perform an automatic 3 shot bracket. (AEB - Auto Exposure Bracket)

But the Photographer can shoot a 6 shot bracket and that is what I advised.

Perhaps I was not clear enough: use M Mode and (the Photographer) Bracket 6 shots.

(or the OP could use the AEB function - making 2 x 3 Auto Exposure Brackets)

WW


PS - Thank you Allan - on re-reading my original I certainly was not clear: especially not clear for an answer to a beginner.

[pnodrog]

Around November 2013, Canon announced that the EOS-1D X was to be the first Canon DSLR to get exposure compensation in Manual mode with ISO Auto. Just after that date CPN and Chuck Westfall (independently) announced that other Firmware Updates would follow for some other EOS cameras, I don't have at hand the (very short) list of those Cameras.

WW

Thanks Bill good to know. They had to catch up sometime...